Rast

Appearance

Playback and practice ​

Rast is designed for the way musicians actually practice: slow a phrase down, drop the key a tone, mute the vocal, count yourself in. Every change happens live as the song is playing — there is no rendering, no waiting, nothing to save.

Already imported a song? Pick it from the sidebar and start with the spacebar.

Transport ​

The transport bar sits below the timeline.

  • Space — play / pause
  • Stop button — return to the start
  • Left arrow — jump back 5 seconds
  • Right arrow — jump forward 5 seconds

The seek bar shows the current position and total length. Drag the playhead, or click anywhere on the bar to jump there.

Scrubbing the timeline ​

The timeline above is interactive too. The playhead stays centered while the song scrolls past it.

  • Click anywhere in the timeline to seek to that moment.
  • Drag to scrub through the song — useful for landing exactly between two beats.
  • Scroll with the mouse wheel to zoom the timeline in or out.

The chord boxes above the waveform show what is being played; the colored band underneath is the vocal and instrumental energy.

Timeline transport

Stem volumes ​

The two sliders under Stems in the controls panel are your mix.

  • Vocals — pull this to zero to practice singing over the band.
  • Instrum. — drop this to play along on guitar or bouzouki without competing.

Scroll the wheel over either slider for fine 5% steps.

Pitch shift ​

Under Key, the + and − buttons (or Up / Down arrows on the keyboard) shift the song in semitones, from −12 to +12. The displayed root note updates to show the transposed key, with the offset (e.g. +3) underneath. Chord labels in the timeline transpose with it. Pitch is changed in real time — no re-render, no quality loss for small shifts.

Speed ​

Under Speed, the slider runs from 50% to 150%. Drag it, or scroll to nudge in 5% steps. The pitch stays put while the tempo changes — perfect for slowing down a fast solo without learning it in the wrong key.

Pitch and speed controls

Metronome ​

Toggle the metronome on with the switch under Metronome. The slider next to it sets click volume.

The dropdown picks the tick pattern:

  • Downbeat — clicks on beats 1 and 3
  • Backbeat — clicks on 2 and 4
  • Every beat — straight quarter notes
  • Subdivide — eighth notes

Tick Count-in to get a free bar of clicks before playback starts after a pause — useful for entering on the right beat after seeking.

Pitch and speed are always live, so you can practice with one hand on the keyboard, dropping the song a tone or shaving off 10% the moment a passage gives you trouble.