WayLoop guides

How to slow down a song without changing its pitch

To slow a song down and keep it in the same key, you need a tool that time-stretches the audio. Open the song in a practice app such as WayLoop, set the speed to about 70%, and every note stays where it was: only the time between them grows.

Why a slowed recording normally sounds lower

Play a tape or a record at half speed and two things happen together: it takes twice as long, and it drops by an octave. The sound's vibrations reach you more slowly, and that is what pitch is. For a musician this is useless, because the notes no longer match your instrument.

Time-stretching separates the two. The software cuts the sound into very short overlapping slices and spreads them out, adjusting them so they still join smoothly. The song takes longer, and its pitch doesn't move.

How to do it in WayLoop

Open the song. WayLoop opens WAV, MP3, FLAC and AIFF files. On a computer you can drop the file on the window; on iPhone and iPad, open it from the Files app.
Pick a speed. Choose 50, 60 or 70% under Speed, or anything from 30% to 200%.
Loop the part you're learning. On a computer, press L where the passage starts and L again where it ends. On iPhone and iPad, tap A and B.
Bring it back up. When you can play it cleanly, raise the speed a little and go again.

Which speed to start at

Start at the fastest speed where you can still play every note correctly, not the slowest one available. For most fast passages that is between 50 and 70%. Below about 50% the rhythm gets hard to feel, and a phrase can stop sounding like itself.

Slowing down always changes the sound a little, more at very slow speeds. Expect some softness on drums and consonants. It's normal, and they are still the same notes in the same key.

If you need a different key too

Speed and key are separate controls. In WayLoop you can move a song up or down by semitones and fine-tune it in cents, for example to match a guitar tuned down a half step, or a recording that runs slightly sharp.

Other ways to do it

YouTube's playback speed keeps the pitch and costs nothing, but it only works on what's on YouTube, and it has no precise loop.
Audacity is free and can render a slowed copy of a file. It works, but you have to render again each time you change speed.
Paid practice apps such as Transcribe!, Amazing Slow Downer and Anytune do this well and have long track records.

Get WayLoop

WayLoop is free, with no ads and no account: App Store for Mac, iPhone and iPad, Microsoft Store for Windows. Android is coming. You can also try it on its page, in your browser.