Slow down any song in three steps
- Import and splitAdd the song to Woodshed. Splitting it into stems is optional for slowing down, but lets you hear one part clearly.
- Set the speedOpen speed and pick 50% or 75%, or step anywhere from 25% to 150% in 5% steps. The pitch does not move.
- Loop and build upSet an A-B loop on the hard passage and turn on the speed trainer, which nudges the tempo up a little each time the loop comes round.
Why slowing down usually changes the pitch
Sound is vibration over time. Play a recording slower and every vibration takes longer, which means a lower frequency and a lower note. That is why a 45 played at 33 sounds like a different, sleepier band.
Time stretching breaks that link. The audio is cut into tiny overlapping slices, each slice is analysed, and the slices are spread further apart in time while their frequencies are kept the same. Good algorithms also track the sharp attack of a drum hit or a picked note, so slowed-down audio still sounds like the instrument rather than a smear.
Woodshed uses a high quality stretching engine running on your device, applied once to the mix of whichever stems you have turned up. Change speed or key mid-song and you hear it straight away.
Which speed should you practise at?
Slow enough to play it perfectly, and no slower. If you are making mistakes at a tempo, you are practising the mistakes. A useful rule: find the speed where you can play the passage cleanly three times in a row, then work up from there.
- 50% for transcribing. Fast runs and ornaments become individual notes you can actually hear.
- 60 to 75% for learning. Your fingers learn the shapes without tensing up.
- 85 to 95% for polishing. Close enough to feel like the real thing, with a little headroom.
- 100 to 110% for confidence. Playing a touch above tempo makes the real speed feel easy on the night.
A routine for getting a fast part up to tempo
Most players slow a song down, get it right once, and jump back to full speed. The part falls apart and they decide they cannot play it. A steadier climb works better.
- Loop only the bar or two that is hard, not the whole solo.
- Start at the clean speed you found above and play the loop five times without a mistake.
- Turn on the speed trainer, or raise the speed by 5% yourself, and repeat.
- If you start fumbling, drop back 10% and climb again. Two steps forward, one back.
- Once the loop is at full speed, widen it to include the bar before and after so you can get in and out of it.
Slow down one instrument, hear it clearly
Slowing the full mix helps, but a buried part is still buried. Because Woodshed splits the song first, you can solo the bass or the guitar and slow just that down. You hear every ghost note and slide that the full mix hides, which makes transcribing far quicker.
When you are ready to play, bring the band back, mute your own stem, and practise at the slowed tempo with everyone else still in time with you. The smart metronome follows the beats in the recording at whatever speed you choose.
Changing the key too
The same engine moves the pitch without touching the tempo. Singers can drop a song a tone to fit their range, and guitarists can match a recording that was tuned down a half step without retuning. Woodshed shifts up or down six semitones and shows you where to put a capo for the new key.
