diff --git a/doc/2-interface/effect-list-window.md b/doc/2-interface/effect-list-window.md
index 6abadae9d..35c738387 100644
--- a/doc/2-interface/effect-list-window.md
+++ b/doc/2-interface/effect-list-window.md
@@ -7,4 +7,7 @@ this window provides a list of the effects that are available.
 for more details about these effects, see [the effects page](../3-pattern/effects.md).
 
 - **Chip at cursor**: the currently selected chip. the list only shows available effects for this chip.
+- filter bar: type to filter the list to show only matching effects.
 - menu button: opens a small list of effect categories. toggle each to change whether effects belonging to such categories will be shown in the list.
+  - **All**: show all effects.
+  - **None**: show no effects.
diff --git a/doc/2-interface/export.md b/doc/2-interface/export.md
index e1619bc92..8e6abc390 100644
--- a/doc/2-interface/export.md
+++ b/doc/2-interface/export.md
@@ -7,16 +7,39 @@ Furnace allows you to export your song in several formats. this section deals wi
 this option allows you to export your song in .wav format. I know I know, no .mp3 or .ogg export yet, but you can use a converter.
 
 - **Export type**:
-  - **one file**: exports your song to one .wav file.
-  - **multiple files (one per chip)**: exports the output of each chip to .wav files.
-  - **multiple files (one per channel)**: exports the output of each channel to .wav files.
-    - useful for usage with a channel visualizer such as corrscope.
-- **Bit depth**: default is 16-bit integer.
-- **Sample rate**: affects the quality of the output file.
-  - default is 44100, "CD quality".
-  - lower sample rates lose fidelity as upper frequencies disappear.
-  - higher sample rates gain frequencies that can't be heard at the cost of file size and rendering time.
-- **Channels in file**: default is 2 (stereo). Set to 1 for mono.
+  - **one file**: exports your song to a single file.
+  - **multiple files (one per chip)**: exports the output of each chip to its own file.
+  - **multiple files (one per channel)**: exports the output of each channel to its own file.
+    - ideal for use with a channel visualizer such as [corrscope](https://github.com/corrscope/corrscope).
+- **File Format**: select the output format. each format has its own options.
+  - **Wave**: lossless uncompressed .wav format. largest file size but perfect quality. most useful for files that will need further editing.
+    - **Bit depth**: default is 16-bit integer.
+    - **Sample rate**: affects the quality of the output file.
+      - default is 44100, "CD quality".
+      - lower sample rates lose fidelity as upper frequencies disappear.
+      - higher sample rates gain frequencies that can't be heard at the cost of file size and rendering time.
+    - **Channels in file**: default is 2 (stereo). Set to 1 for mono.
+  - **Opus**: lossy compressed .opus format. smaller size than either MP3 or Vorbis for better quality sound, but less common support than other formats.
+    - **Channels in file**: default is 2 (stereo). Set to 1 for mono.
+    - **Bit rate**: higher numbers generate better quality sound and larger file size. default is 128000.
+  - **FLAC (Free Lossless Audio Codec)**: lossless compressed .flac format. good for archival or editing, as it preserves original sound data.
+    - **Sample rate**: affects the quality of the output file. see above.
+    - **Channels in file**: default is 2 (stereo). Set to 1 for mono.
+    - **Compression level**: higher levels take slightly longer to pack but yield much better compression. default is 6.0.
+  - **Vorbis**: lossy compressed .ogg format. better quality sound than MP3 with smaller file size. fairly common support
+    - **Sample rate**: affects the quality of the output file. see above.
+    - **Channels in file**: default is 2 (stereo). Set to 1 for mono.
+    - **Quality**: compression rate. higher numbers produce larger files of higher fidelity. default is 8.0.
+  - **MP3**: lossy compressed .mp3 format. it's the old standard; worst quality for the file size, but it sees the most widespread support and use.
+    - **Sample rate**: affects the quality of the output file. see above.
+    - **Channels in file**: default is 2 (stereo). Set to 1 for mono.
+    - **Bit rate mode**:
+      - **Constant**: fixed bit rate regardless of content. default.
+        - **Bit rate**: higher numbers generate better quality sound and larger file size. default is 128000.
+      - **Variable**: bit rate adapts to the content. generates smaller files for the same quality.
+        - **Quality**: higher numbers produce larger files of higher fidelity. default is 6.0.        
+      - **Average**: a compromise; the steady bit rate of "constant" with higher quality, but less efficiently compressed than "variable".
+        - **Bit rate**: higher numbers generate better quality sound and larger file size. default is 128000.
 - **Loops**: sets the number of times the song will loop.
   - does not have effect if the song ends with `FFxx` effect.
 - **Fade out (seconds)**: sets the fade out time when the song is over.
diff --git a/doc/2-interface/keyboard.md b/doc/2-interface/keyboard.md
index 48f2bcb59..01348f407 100644
--- a/doc/2-interface/keyboard.md
+++ b/doc/2-interface/keyboard.md
@@ -33,6 +33,7 @@ the keys in the "Global hotkeys" section can be used in any window, although not
 | Decrease edit step                                     | `Ctrl-Keypad /`  |
 | Toggle edit mode                                       | `Space`          |
 | Metronome                                              | `Ctrl-M`         |
+| Toggle order lock                                      | —                |
 | Toggle repeat pattern                                  | —                |
 | Follow orders                                          | —                |
 | Follow pattern                                         | —                |
@@ -75,6 +76,9 @@ the keys in the "Global hotkeys" section can be used in any window, although not
 | Effect List                                            | —                |
 | Debug Menu                                             | `Ctrl-Shift-D`   |
 | Command Stream Player                                  | —                |
+| Reference Music Player                                 | —                |
+| Tuner                                                  | —                |
+| Spectrum                                               | —                |
 | About                                                  | —                |
 | Collapse/expand current window                         | —                |
 | Close current window                                   | `Shift-Escape`   |
diff --git a/doc/2-interface/menu-bar.md b/doc/2-interface/menu-bar.md
index f6c776fde..01ad2bc09 100644
--- a/doc/2-interface/menu-bar.md
+++ b/doc/2-interface/menu-bar.md
@@ -115,6 +115,8 @@ all these menu items show or hide their associated windows.
   - **[oscilloscope (per-channel)](../8-advanced/chanosc.md)**
   - **[oscilloscope (X-Y)](../8-advanced/xyosc.md)**
   - volume meter
+  - **[tuner](../8-advanced/tuner.md)**
+  - **[spectrum](../8-advanced/spectrum.md)**
 - tempo
   - **[clock](../8-advanced/clock.md)**
   - **[grooves](../8-advanced/grooves.md)**
@@ -127,6 +129,8 @@ all these menu items show or hide their associated windows.
 - **[effect list](../3-pattern/effects.md)**
 - **[play/edit controls](play-edit-controls.md)**
 - **[piano/input pad](../8-advanced/piano.md)**
+- **[reference music player](../8-advanced/refPlayer.md)**
+- **[multi-ins setup](../8-advanced/multi-ins.md)**
 
 ## help
 
diff --git a/doc/2-interface/play-edit-controls.md b/doc/2-interface/play-edit-controls.md
index d35fdb723..733158a26 100644
--- a/doc/2-interface/play-edit-controls.md
+++ b/doc/2-interface/play-edit-controls.md
@@ -8,10 +8,14 @@ the "Play/Edit Controls" are used to control playback and change parameters of t
 - ![play repeat](control-play-repeat.png) **Repeat from the beginning of this pattern**: repeats current pattern from its start.
 - ![step](control-step.png) **Step one row**: plays only the row at cursor position and moves down one.
 - ![edit](control-edit.png) **Edit**: toggles edit mode. when turned off, you won't be able to enter notes.
-- ![lock](control-lock.png) **Lock**: toggles the cursor lock, which keeps the cursor in the currently selected order.
+- ![lock](control-lock.png) **Lock**: toggles the order lock, which keeps the cursor in the currently selected order.
 - ![metronome](control-metronome.png) **Metronome**: toggles the metronome, which only works during playback.
 - ![repeat](control-repeat.png) **Repeat pattern**: toggles pattern repeat. during playback while this is on, the current pattern will play over and over instead of following the order list.
-- **Poly**: turns on polyphony for previewing notes. toggles to **Mono** for monophony (one note at a time only).
+- polyphony toggle: cycles through the following options.
+  - **Mono**: monophony. preview one note at a time only.
+  - **Poly**: polyphony. preview multiple notes at once, using other channels of the same type on the same chip. default.
+  - **Chord**: chord input. as polyphony, with the added feature that while keys are held, notes past the first are entered on the same row in adjacent channels.
+    - some keyboards have limits on the number of keys that can be held at the same time. this is not a Furnace issue.
 - **Octave**: sets current input octave.
 - **Edit Step**: sets edit step. if this is 1, entering a note or effect will move to the next row. if this is a larger number, rows will be skipped. if this is 0, the cursor will stay in place.
   - if clicked, Step becomes **Coarse**, which sets the number of rows moved with `PgUp`, `PgDn`, and related movement shortcuts. clicking again will revert it to Step.
diff --git a/doc/2-interface/settings.md b/doc/2-interface/settings.md
index d03200e26..fb7804559 100644
--- a/doc/2-interface/settings.md
+++ b/doc/2-interface/settings.md
@@ -87,6 +87,7 @@ settings are saved when clicking the **OK** or **Apply** buttons at the bottom o
 - **New instruments are blank**: when enabled, adding FM instruments will make them blank (rather than loading the default one).
 
 ### Configuration
+
 - **Import**: select an exported `.ini` config file to overwrite current settings.
 - **Export**: select an `.ini` file to save current settings.
 - **Factory Reset**: resets all settings to default and purges settings backups.
@@ -94,6 +95,7 @@ settings are saved when clicking the **OK** or **Apply** buttons at the bottom o
 ### Import
 
 - **Use OPL3 instead of OPL2 for S3M import**: changes which system is used for the import of S3M files that contain FM channels.
+- **Load sample fine tuning when importing a sample**: as it says. may result in glitches with some samples.
 
 ## Audio
 
@@ -103,6 +105,8 @@ settings are saved when clicking the **OK** or **Apply** buttons at the bottom o
   - SDL: the default one.
   - JACK: the JACK Audio Connection Kit (low-latency audio server). only appears on Linux, or MacOS compiled with JACK support.
   - PortAudio: this may or may not perform better than the SDL backend.
+  - ASIO: Audio Stream Input/Output. extremely low latency, if your system has a driver for it. after selecting it, click "Apply" to see available devices.
+    - **Control Panel**: opens the ASIO driver's control panel. you must first select a device and click "Apply".
 - **Driver**: select a different audio driver if you're having problems with the default one.
   - only appears when Backend is SDL.
 - **Device**: audio device for playback.
@@ -576,6 +580,16 @@ below all the binds, select a key from the dropdown list to add it. it will appe
 
 - **Show channel indicators**: chooses whether to show the row "LED" channel indicators in the chip manager.
 
+### Mixer
+
+- **Mixer layout:**
+  - **Horizontal**: a horizontal arrangement of tall mixer sliders.
+  - **Vertical**: a vertical stack of wide mixer sliders. default.
+- **Mixer style:**
+  - **No volume meters**
+  - **Volume meters separate**: default.
+  - **Volume meters in volume sliders**
+
 ### Windows
 
 - **Rounded window corners**
diff --git a/doc/4-instrument/macro-ADSR.png b/doc/4-instrument/macro-ADSR.png
index df3ff43fa..ad5c6ef15 100644
Binary files a/doc/4-instrument/macro-ADSR.png and b/doc/4-instrument/macro-ADSR.png differ
diff --git a/doc/4-instrument/macro-LFO.png b/doc/4-instrument/macro-LFO.png
index 4d9d195d3..480493708 100644
Binary files a/doc/4-instrument/macro-LFO.png and b/doc/4-instrument/macro-LFO.png differ
diff --git a/doc/6-sample/README.md b/doc/6-sample/README.md
index cd2f5ddbd..cef846130 100644
--- a/doc/6-sample/README.md
+++ b/doc/6-sample/README.md
@@ -100,19 +100,13 @@ in there, you can modify certain data pertaining to your sample, such as the:
 - **no BRR filters**: when encoding to BRR, only use a "4-bit mode" with block filter set to 0.
   - this allows usage of sample offset effects on SNES.
   - only appears when applicable.
-
-- **Rate**: switches to normal rate values.
-- **Compat Rate**: switches to DefleMask-compatible rate values for sample mapping.
-  - **use of this is discouraged!**
 - **Hz**: base frequency of sample played at `C-4`.
 - **Note**: note corresponding to Hz.
-- **Fine**: fine tuning. ranges from -64 to 63, which maps to -1 to almost +1 semitone.
-
+- **Fine**: fine tuning. ranges from -64 to 63, which maps from -1 to almost +1 semitone.
 - **Loop**: enable or disable sample loop. only on supported chips.
 - **Mode**: direction of loop. backward and ping pong loops are only natively available on some chips.
-- **Start**: start of loop.
-- **End**: end of loop.
-
+- **Start**: start of loop. if the sample is on a chip that limits loop points to specific values, hovering over this will highlight them in the editor.
+- **End**: end of loop. similarly, hovering will highlight valid loop points.
 - **Chips:** set assignment to chips and sample banks.
   - sample will only be uploaded to selected chips.
   - columns correspond to chips in use.
@@ -125,17 +119,20 @@ in there, you can modify certain data pertaining to your sample, such as the:
 - **Resize**: stretches sample. pops up a dialog to type new length.
 - **Resample**: stretches sample. pops up a dialog box:
   - **Rate**: new sample rate.
+  - **Length**: new sample length.
+  - **Factor**: multiplier of original sample rate.
   - **0.5x**: halves sample rate.
   - **==**: returns to original sample rate.
   - **2.0x**: doubles sample rate.
-  - **Factor**: multiplier of original sample rate.
   - **Filter**: selects interpolation filter for resampling.
 - **Undo**: undoes previous edit.
 - **Redo**: redoes undone edit.
-- **Amplify**: changes amplitude of selection. pops up a dialog to type amount.
+- **Amplify/Offset**: pops up a dialog to enter amounts.
+  - **Volume**: amplifies selection.
+  - **DC Offset**: shifts selection up (positive values) or down (negative values).
 - **Normalize**: adjusts amplitude of selection to maximum without clipping.
-- **Fade in**: ramp amplitude of selection from 0 to original.
-- **Fade in**: ramp amplitude of selection from original to 0.
+- **Fade in**: ramps amplitude of selection from 0 to original.
+- **Fade in**: ramps amplitude of selection from original to 0.
 - **Insert silence**: inserts silence. pops up a dialog to type length.
 - **Apply silence**: reduces amplitude of selection to 0.
 - **Delete**: removes selection.
@@ -173,3 +170,8 @@ in the sample viewer:
   - **paste (mix)**: mixes the sample clipboard into the existing sample, beginning at the start of the selection.
   - **set loop to selection**: changes loop region to match selection.
   - **create wavetable from selection**: copies the selection into a new wavetable entry.
+
+in the bottom status bar:
+- **Select**: set selection start and end positions using the two numeric entry boxes. total selection length will be shown next to them.
+- cursor position and sample value.
+- loop size in samples and bytes.
diff --git a/doc/6-sample/sample-editor.png b/doc/6-sample/sample-editor.png
index 7003de69d..6777dec90 100644
Binary files a/doc/6-sample/sample-editor.png and b/doc/6-sample/sample-editor.png differ
diff --git a/doc/7-systems/pce.md b/doc/7-systems/pce.md
index 26820c169..6c72f9e15 100644
--- a/doc/7-systems/pce.md
+++ b/doc/7-systems/pce.md
@@ -36,5 +36,5 @@ the following icons are displayed when channel status is enabled in the pattern
 the following options are available in the Chip Manager window:
 
 - **Pseudo-PAL**: run the chip on a PAL clock. such a configuration has (probably) never existed, despite a planned official PAL version of the PC Engine.
-- **Disable anti-click**: waveform switching requires a phase reset, which may cause clicks. Furnace uses a wave-position predicting algorithm to minimize these clicks. enable this option to disable it.
+- **Disable anti-click**: waveform switching requires a phase reset, which may cause clicks. Furnace uses a wave-position predicting algorithm to minimize these clicks. enable this option to turn off the feature.
 - **Chip revision**: sets the chip revision. HuC6280A has less pops.
diff --git a/doc/7-systems/watarasv.md b/doc/7-systems/watarasv.md
index 75364184f..876f996ce 100644
--- a/doc/7-systems/watarasv.md
+++ b/doc/7-systems/watarasv.md
@@ -15,7 +15,9 @@ this chip uses the [Watara Supervision](../4-instrument/watarasv.md) and [Generi
 
 ### sample info
 
-the sample channel is a 4-bit DMA channel with 4 frequencies assigned to sample octaves (C2, C3, C4, C5; C, C#, D, D# in Furnace respectively). max sample size is 4 kilobytes (8192 samples), samples are padded to multiples of 32 samples, and loop points are ignored.
+the sample channel is a 4-bit DMA channel with 4 playback frequencies (1953.125, 3906.25, 7812.5, and 15625) assigned to the notes C, C#, D, and D# in all octaves.
+
+max sample size is 4 kilobytes (8192 samples), samples are padded to multiples of 32 samples, and loop points are ignored.
 
 ## chip config
 
diff --git a/doc/8-advanced/channels.md b/doc/8-advanced/channels.md
index 53bc00065..ecf19330e 100644
--- a/doc/8-advanced/channels.md
+++ b/doc/8-advanced/channels.md
@@ -7,7 +7,7 @@ the "Channels" dialog allows manipulation of the song's channels.
 each channel has the following options:
 - **Pat**: uncheck the box to hide the channel from the pattern view. pattern data will be kept.
 - **Osc**: uncheck the box to hide the channel from the per-channel oscilloscope view.
-- **Swap**: click and drag to rearrange pattern data throughout the song.
+- crossed arrows buttons: click and drag to rearrange pattern data throughout the song.
   - note: this does **not** move channels around! it only moves the channel's pattern data.
 - **Name**: the name displayed at the top of each channel in the pattern view.
 - the next setting is "short name", which is displayed in the orders view and/or when a channel is collapsed.
diff --git a/doc/8-advanced/channels.png b/doc/8-advanced/channels.png
index 9fc26fde5..fc0cf4ae9 100644
Binary files a/doc/8-advanced/channels.png and b/doc/8-advanced/channels.png differ
diff --git a/doc/8-advanced/mixer-mixer.png b/doc/8-advanced/mixer-mixer.png
index 01dfdc5c7..198a8f36d 100644
Binary files a/doc/8-advanced/mixer-mixer.png and b/doc/8-advanced/mixer-mixer.png differ
diff --git a/doc/8-advanced/mixer-patchbay.png b/doc/8-advanced/mixer-patchbay.png
index ff36d9d07..4812c776c 100644
Binary files a/doc/8-advanced/mixer-patchbay.png and b/doc/8-advanced/mixer-patchbay.png differ
diff --git a/doc/8-advanced/mixer.md b/doc/8-advanced/mixer.md
index 03883e6ad..c18d5de6d 100644
--- a/doc/8-advanced/mixer.md
+++ b/doc/8-advanced/mixer.md
@@ -4,24 +4,17 @@ the "Mixer" dialog provides options for overall sound mixing.
 
 ## "Mixer" tab
 
-![mixer dialog on mixer tab](mixer-mixer.png) <!--new image(s) needed!-->
+![mixer dialog on mixer tab](mixer-mixer.png)
 
 **Master Volume** controls the overall mix.
 
 each chip has several options:
-- **Invert**: flips the output wave.
-- **Volume**: controls the chip's volume relative to other chips.
-- **Panning**: left-right sound control.
-- **Front/Rear**: front-read sound control. only useful for setups with four or more speakers.
+- **invert**: inverts the output wave.
+- **volume**: controls the chip's volume relative to other chips.
+- **panning**: left-right balance.
+- **fade**: front-rear balance. only useful for setups with four or more speakers.
 
-### Mixer-specific settings <!--in settings-->
-- **Mixer layout**: how the mixer is shown.
-  - **Horizontal**: arranges the "chips"<!--reword!--> horizontally, with vertical volume sliders.
-  - **Vertical**: arranges the "chips"<!--ditto--> vertically, with horizontal volume sliders.
-- **Mixer style**:
-  - **No volume meters**: does not show per-chip volume meters.
-  - **Volume meters separate**: shows per-chip volume meters below or to the right (depending on the layout) of the volume slider.
-  - **Volume meters in volume sliders**: shows per-chip volume meters inside the volume sliders.
+settings for the mixer display can be found in Settings > Appearance near the bottom.
 
 ## "Patchbay" tab
 
diff --git a/doc/8-advanced/multi-ins.md b/doc/8-advanced/multi-ins.md
index 30f22c17b..c49e071af 100644
--- a/doc/8-advanced/multi-ins.md
+++ b/doc/8-advanced/multi-ins.md
@@ -1,11 +1,11 @@
 # multi-instrument playback
 
-the instrument list allows you to select more than one instrument by shift-clicking. doing so engages multi-instrument playback mode, where note input will play multiple instruments at once.
+the instrument list allows you to select up to 8 instruments by shift-clicking. doing so engages multi-instrument playback mode, where note input will play multiple instruments at once (as channel limits allow).
 
-the following window also appears, allowing you to set the note offset (in semitones) for each instrument:
+the following window also appears.
 
-```
-TODO: IMAGE!
-```
+![multi-instrument setup](multi-ins.png)
 
-up to 8 instruments can be played at a time.
+clicking the arrows will set the note offset (in semitones) for each selected instrument. clicking a column resets it to zero. right-clicking the arrows will change their value by a full octave.
+
+multi-instrument playback cannot be used while polyphony is set to "Mono".
diff --git a/doc/8-advanced/multi-ins.png b/doc/8-advanced/multi-ins.png
new file mode 100644
index 000000000..e6d73d15a
Binary files /dev/null and b/doc/8-advanced/multi-ins.png differ
diff --git a/doc/8-advanced/pattern-manager.png b/doc/8-advanced/pattern-manager.png
index 3ac440cb6..7502847a6 100644
Binary files a/doc/8-advanced/pattern-manager.png and b/doc/8-advanced/pattern-manager.png differ
diff --git a/doc/8-advanced/piano.md b/doc/8-advanced/piano.md
index 302177e0a..a72d25b7e 100644
--- a/doc/8-advanced/piano.md
+++ b/doc/8-advanced/piano.md
@@ -24,10 +24,25 @@ right-clicking on the piano keys will make the buttons disappear; right-clicking
 
 ## options
 
-key layout:
+**Key layout:**
 - **Automatic**
 - **Standard**: black keys are 2/3 length.
 - **Continuous**: black keys are full length.
 
+**Value input pad:**
+- **Disabled**
+- **Replace piano**: replaces the piano with buttons for hexadecimal numeric entry when needed (when the pattern editor's cursor is in a hex column).
+- **Split (automatic)**: displays a separate entry pad when needed.
+- **Split (always visible)**: always displays the entry pad.
+
+**Key labels:**
+- **Off**
+- **Octaves**
+- **Notes**
+- **Notes (with octave)**
+- **Octaves (with C)**
+- **Notes + Octaves**
+
 **Share play/edit offset/range**: if disabled, the piano will keep different octave and range values for playback and non-playback states.
-**Read-only (can't input notes): prevents note entry.
+
+**Read-only (can't input notes)**: prevents note entry.
diff --git a/doc/8-advanced/refPlayer.md b/doc/8-advanced/refPlayer.md
index 6677a3d8a..c567b90ac 100644
--- a/doc/8-advanced/refPlayer.md
+++ b/doc/8-advanced/refPlayer.md
@@ -1,6 +1,21 @@
 # reference music player
 
 the Music Player window is a small audio player that can synchronize with the tracker playback.
-<!--IMAGE
-![reference music player window]()-->
-<!--TODO: the rest-->
+
+![reference music player window](reference.png)
+
+below the time is the playback bar which can be used to scrub through the loaded file.
+
+below that, from left to right:
+- open file: choose an audio file to play.
+- cue.
+  - left click: set the cue position. this attaches the current time in the reference file to the position of the cursor in the pattern editor.
+  - middle click: jump to the beginning of the reference track.
+  - right click: opens a numeric entry box to set the cue position (offset between the tracker and the reference).
+- play/pause.
+- preview.
+  - left click and hold to play the reference file from the correponding position of the current order.
+  - right click and hold to play the reference file from the correponding position of the pattern editor's cursor.
+  - **Sync**: toggles synchronization of reference playback with tracker playback.
+  - **Mix:**: changes how loud the reference file is compared to the tracker.
+  
\ No newline at end of file
diff --git a/doc/8-advanced/reference.png b/doc/8-advanced/reference.png
new file mode 100644
index 000000000..5f02893bb
Binary files /dev/null and b/doc/8-advanced/reference.png differ
diff --git a/doc/8-advanced/spectrum.md b/doc/8-advanced/spectrum.md
index 8a315d8dd..f0f44454d 100644
--- a/doc/8-advanced/spectrum.md
+++ b/doc/8-advanced/spectrum.md
@@ -2,21 +2,16 @@
 
 the Spectrum window shows the frequency spectrum of the audio output.
 
-<!--IMAGE
-![spectrum window]()-->
+![spectrum window](spectrum.png)
 
-<!--somehow make this info work-->
-the X scale is in Hertz, and the Y scale is in decibels.
+the X axis (horizontal logarithmic scale) is frequency in Hz, and the Y axis (vertical linear scale) is amplitude in decibels.
 
-clicking the threeline <!--REPLACE--> button in the top left corner open its configuration.
-- **Mono**: whether to mix all the output for a single graph.
-- **Bins**: number of bins for the FFT calculation.
----
+clicking the three-line "hamburger" button in the top right corner opens a configuration dialog.
+- **Mono**: mix all output together to display a single line.
+- **Bins**: number of bins for the FFT calculation. higher numbers increase frequency resolution but decrease temporal resolution (slower response).
 - **X Zoom**: how much to zoom the X axis.
-- **X Offset**: how much to move the X axis.
----
+- **X Offset**: how much to move the X axis horizontally.
 - **Y Offset**: how much to move the Y axis down.
----
 - **Show X Grid**: whether to show the X axis grid lines.
 - **Show Y Grid**: whether to show the Y axis grid lines.
 - **Show X Scale**: whether to show the X axis scale.
diff --git a/doc/8-advanced/spectrum.png b/doc/8-advanced/spectrum.png
new file mode 100644
index 000000000..303b88ba0
Binary files /dev/null and b/doc/8-advanced/spectrum.png differ
diff --git a/doc/8-advanced/tuner.md b/doc/8-advanced/tuner.md
index 233a09dd0..e8810a89b 100644
--- a/doc/8-advanced/tuner.md
+++ b/doc/8-advanced/tuner.md
@@ -2,5 +2,10 @@
 
 the Tuner window shows the approximate frequency and note of the audio output.
 
-<!-- IMAGE
-![tuner window]()-->
+![tuner window](tuner.png)
+
+the meter at the top shows how close the note is to center pitch.
+
+the center displays the approximate note, followed by the calculated peak frequency in Hz and how far from center pitch it is in cents (hundredths of a semitone).
+
+the piano keyboard shows the approximate note.
\ No newline at end of file
diff --git a/doc/8-advanced/tuner.png b/doc/8-advanced/tuner.png
new file mode 100644
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