Choir Mixer
Getting Started Guide
v3.8.15 · davekauffman.ca
Overview
Choir Mixer is a browser-based tool for practising choral music. It plays separate audio tracks for each vocal part — Soprano, Alto, Tenor, Bass, or whatever parts your choir uses — and lets each singer control the mix independently. You can isolate your own part, loop a tricky section, slow the tempo without changing pitch, navigate between rehearsal markers, and adjust the balance to suit your ear.
Every setting you make is saved automatically in your browser and restored the next time you open the page. Your settings are yours alone — no one else sees them.
The Interface
Song Selector
The song title at the top of the page is a dropdown. Tap it to see all available songs and switch between them. The mixer reloads with the correct tracks and any markers or loop settings you previously saved for that song.
Transport Bar
The transport bar contains the main playback controls.
- Play / Pause — starts or pauses playback. The button toggles between the two states.
- Stop — stops playback. In loop mode, the playhead returns to the loop in-point; otherwise it returns to the beginning of the song.
- Loop — enables loop mode (see the Loop section below).
- Speed — a slider that slows playback from 100% down to 25%, preserving the original pitch.
- Pitch — a dropdown that shifts the key up or down by up to three semitones.
- Export Mix — saves the current mix as a WAV file at the current speed and pitch settings.
The spacebar on your keyboard also toggles play and pause from anywhere on the page.
The status indicator at the right of the transport bar shows Ready, Playing, Paused, or Calculating… when audio is being processed. A small red dot may appear beside the status text on very loud passages — this indicates the automatic limiter is working to prevent distortion.
The Speed percentage and Pitch dropdown change colour to reflect their state. Grey means the control is at its default value (100% or Original). Amber means a change has been requested and the audio is being processed. Green means a non-default value is active and the audio matches what the control shows.
Scrubber
The scrubber bar shows where you are in the song. The left counter shows elapsed time, the right shows time remaining.
- Click or tap anywhere on the scrubber to jump to that position.
- Drag the thumb to scrub through the song.
- The scrubber snaps to nearby markers as you drag — useful for landing precisely on a section boundary.
- While loop mode is active, the thumb is constrained to the loop region during playback.
Waveform
A small disclosure triangle labelled “Waveform” sits below the loop handles. Click it to expand a visual waveform of the mixed audio, calculated using your current volume and pan settings.
- The waveform reflects exactly what the Export Mix button would produce.
- When loop mode is active, the loop zone is highlighted in blue.
- The green playhead cursor tracks your position in real time. You can drag it directly on the waveform to seek.
- The waveform updates automatically when you adjust volume or pan.
Markers
Amber downward triangles (▾) on the scrubber mark rehearsal points such as Verse, Chorus, or section letters A, B, C.
- Single-click a marker to jump the playhead to that position.
- Double-click a marker to set the loop region from that marker to the next one and enable loop mode automatically.
Loop Row
Below the scrubber is the loop row — a thin line with two triangular handles. The in-point handle sets where the loop starts; the out-point handle sets where it ends. The region between them is shaded blue when loop mode is active.
- Click anywhere on the loop row (not on a handle) to enable loop mode and set the in-point at that position.
- Drag either handle to adjust the loop boundaries. The in-point snaps to nearby markers; the out-point moves freely.
- While dragging the in-point forward, you will hear audio from the new position so you can find the right entry point by ear.
- While dragging the in-point backward, audio pauses and resumes automatically once you stop moving.
Press L on your keyboard to toggle loop mode on or off without touching the mouse.
When you stop playback while in loop mode, the playhead returns to the loop in-point so you are always ready to resume from the beginning of the section. If you place the scrubber at a specific position before pressing Play, that position is respected.
Speed Control
The Speed slider slows the music down while keeping the pitch exactly the same. Drag the slider left to reduce speed down to 25%. The percentage display turns amber while processing, then green once the audio is ready. Playback resumes automatically from where you were.
When loop mode is on, only the loop region is processed — which is much faster than processing the whole song.
The Export Mix button saves the current mix as a WAV file at whatever speed and pitch are set, so you can practise offline.
Pitch Control
The Pitch dropdown shifts the key of the entire song up or down by up to three semitones, without affecting the tempo. Select a value from the dropdown: −3 to +3 semitones, with Original in the middle. The dropdown turns amber while processing, then green once the new pitch is active. Pitch and speed can be combined freely.
Track Cards
Each vocal part has its own track card showing the part name, a level meter, a volume slider, a pan slider, a Solo button, and a Mute button.
Volume
Drag the Vol slider to raise or lower the volume of that part relative to the others. Your setting is saved automatically and restored when you return to the song.
Pan
Drag the Pan slider between L (left) and R (right) to position that voice in the stereo field. Pan settings are saved along with volume and restored when you return to the song. The default positions are spread automatically to make the parts easy to distinguish in headphones.
Solo
Press and hold the Solo button to hear only that part. Release to restore all tracks. Solo is a push-to-hear control — it is only active while you hold it down.
Mute
Click the Mute button to silence a track completely. The button latches — click once to mute, click again to restore. When muted, the button turns red and the level meter drops to zero. The volume fader position is unaffected — your carefully adjusted level is preserved and restored the moment you unmute.
Mute state is not saved between sessions — all tracks start unmuted when you return to the page.
Export Mix
The Export Mix button saves the current mix as a WAV file. The file reflects your current settings:
- Muted tracks are silent in the exported file. Mute everything except your own part to export just that voice.
- The filename includes the speed and pitch settings when they are not at their defaults — for example PinkSky-75%-2s.wav tells you the file is at 75% speed and two semitones down.
- Exported files contain embedded information including the song title, export date, and any speed or pitch settings applied.
Exporting in Loop Mode
When you press Export Mix while in loop mode with loop markers set, the mixer asks what you want to export:
- Export Loop Zone — exports just the section between the loop markers as a short clip. The filename ends with -loop.
- Export Full Song — exports the complete song at the current speed and pitch. The mixer renders the full song first — you will see the progress bar and the waveform fill out, exactly as if you pressed Play outside loop mode.
- Cancel — returns to the mixer without exporting.
After exporting the full song, the waveform stays filled and the loop zone is restored. If you export again at the same settings, the export is instant — the render is already done.
Keyboard Shortcuts
Keyboard shortcuts work from anywhere on the page except when a text field is focused.
- Space — Play / Pause
- L — Toggle Loop mode on or off
- Tab — Jump to the next marker
- Shift + Tab — Jump to the previous marker
If the playhead is within half a second after a marker, Shift+Tab skips that marker and goes to the one before it.
Your Saved Settings
The mixer remembers the following things between sessions, stored in your browser:
- Which song you were last listening to.
- Your volume and pan settings for each part, per song.
- Your loop in-point and out-point, per song.
The following reset each session:
- Loop mode on/off — the markers are remembered, but whether looping was active is not.
- Speed — always returns to 100% when you reload or switch songs.
- Pitch — always returns to Original when you reload or switch songs.
- Mute — all tracks start unmuted.
Settings are stored locally in your browser on your device. Clearing your browser storage or using a different browser will reset your settings to defaults.
Sheet Music
If a PDF of the sheet music has been linked for the current song, an amber underlined link will appear at the bottom of the page. Tap it to open the PDF in a new tab.
Practice Tips
Learning your part
Solo your part to hear it alone, then release to hear how it sits in the full mix. Use Mute to silence parts that are distracting while you focus on your own line.
Tricky passages
Double-click the marker at the start of a difficult section to instantly loop between that marker and the next. Reduce the speed slider to 75% or lower, then press Play. The passage will repeat continuously at the slower tempo. Gradually increase the speed as your confidence grows.
Practising away from home
Set your speed and pitch, then press Export Mix. The WAV file can be played on any device with no internet connection. The filename tells you exactly what settings were applied. If you are working on a specific passage, set your loop markers and choose Export Loop Zone to get just that section as a short clip.
Adjusting pitch for your voice
If the song sits a little high or low, try shifting the pitch by one semitone. You can combine a pitch shift with a speed reduction and both are applied in a single pass — no extra wait.
Fine-tuning the loop
Drag the in-point handle to the right while playing — you will hear the section from the new start point in real time. Drag it left and the audio pauses momentarily until you settle, then resumes. The out-point moves freely without snapping.
Choir Mixer v3.8.15 · davekauffman.ca
