You need three things: a marker pair around the section, a loop that respects those markers, and a way to slow it down without changing pitch. In JamCrate you Alt-click the waveform to drop an In/Out pair, click the fragment chip to loop exactly that piece, use ⌥⌘[ and ⌥⌘] to jump between markers, and drag the tempo down to 0.5× while the pitch stays put. The whole loop lives inside the song — nothing is re-imported, nothing is re-encoded.
Why replaying the whole track does not work
A three-minute track with a sixteen-bar solo gives you maybe twenty seconds of material to fix. Every time you restart, you spend the first two minutes playing things you can already play, and by the time the hard part arrives your hands are cold and you are watching the counter instead of the phrase. Seeking by hand is worse: you overshoot, you lose the downbeat, and you practise the recovery instead of the bar.
The workflow, end to end
- Play the track and hit M where the solo starts. One keystroke at the moment you hear it — no scrubbing back to find the spot.
- Alt-click the waveform to drop an In/Out pair around the bars you cannot play yet. You get two flags on the wave; drag either one to move it, double-click it to delete it.
- Two nearby markers become a fragment chip. Click the chip to loop just that piece. Nothing outside the markers plays.
- Slow it down. Take the tempo to 0.5× — the pitch does not move, so you are still playing the same notes in the same key, just with time to think.
- Walk between the markers. ⌥⌘[ and ⌥⌘] jump to the previous and next marker, so you can drill the transition into and out of the solo instead of only the solo itself.
- Raise the tempo when it is clean. The marker stays where it is. Tomorrow you open the song and the section is still marked.
Loop one fragment, or skip the gaps
These are two different practice modes and it is worth knowing which one you want.
- Loop repeats a single fragment until you stop it. Use it for the four bars that will not come out.
- Frags plays the marked fragments in order and skips everything between them. Use it when the hard parts are scattered: you hear intro, then the two solos, then the outro — and none of the verses you already know.
Doing it without a dedicated app
It is possible, and if it works for you there is no reason to install anything.
| Tool | Section loop | Catch |
|---|---|---|
| YouTube | no | you can repeat the whole video, not bars 33–48. The video is also not on your disk. |
| QuickTime | no | plays and can run slower, but has no markers and no section repeat. |
| Audacity | yes | select the region and loop-play it — but you are now working in an audio editor, and the markers are not attached to a song. |
| A DAW (Reaper, Logic) | yes | region looping is excellent, and it is a lot of software to open for four bars. |
Loops on your phone as well
If you practise away from the Mac, the same marked fragments can run on a phone in the same Wi-Fi: the set opens from a QR code, the audio streams from the Mac, and the solo loops and transport work on the phone screen. Your files are not copied to the phone for that.
Try it on a track you already own
JamCrate is a free beta for macOS 14+. Import a folder of backing tracks, mark a solo, loop it, slow it down.
Download for Mac Try the player in your browser
About 6 MB · Universal build · signed and notarized by Apple · no account, nothing leaves your Mac.
Prefer Homebrew? brew install --cask vitas/jamcrate/jamcrate
Questions
How long does it take to mark a solo?
One pass through the track: press M when the solo starts, Alt-click the two ends. The markers are saved with the song, so you do it once and never again.
Do markers survive a backup or a library move?
Yes. Markers, links, notes, setlists and rigs travel with the song; a backup is one verified .jamcrate.zip, and the whole library folder can be moved to another disk or Mac.
What if I mark the wrong spot?
Drag the flag to move it, double-click it to delete it. Nothing is destructive — the audio file is never modified.