How to Slow Down Music to Practice an Instrument
To slow down music to practice an instrument, clip the passage you keep fumbling, run it through the Speed Changer at around 0.70×, and loop it until it's clean. Then export it again at 0.80×, 0.90×, and finally full speed. The pitch stays where it was the whole time, so you can play along in tune, and your audio never leaves your device.
Slowing a track down is easy. Turning that into a practice routine that gets you back to full tempo is the part most people skip. This guide is the routine.
What you'll need
- The song as an audio file you already have on your device (MP3, WAV, and most formats your browser can play will work).
- Your instrument, tuned to the recording.
- A media player that can loop a file. Most phone and desktop players have a repeat-one button, and that's enough.
If you want to know why the pitch doesn't drop when the tempo does, how to slow down a song without changing pitch covers the mechanics. This post is about using it to practice.
Step 1: Cut out the passage you're stuck on
Practicing a whole four-minute song at 70% wastes most of your time on parts you can already play. Isolate the hard bit first.
Open the Audio Cutter and load the song. Drag the Trim Start point and Trim End point sliders around the passage, then press Play Selection to check the edges. Leave a bar or so of lead-in before the tricky part so you have time to get your hands in position. When it sounds right, hit Cut & Download (WAV is the default and a sensible choice here).
One thing to know up front: the Speed Changer has no loop or A-B region feature. It plays and exports the whole file you give it. That's why the cut comes first. A short clip makes looping trivial later. How to cut a sample or loop from a song has more on getting clean edit points.
Step 2: Find the tempo (optional, but useful)
If you practice with a metronome, you want to know the original BPM. Drop the full song into the BPM Finder, or see how to find the BPM of any song for the manual methods.
The Speed Changer works in ratios, not BPM, so convert with simple division. A 140 BPM song at 0.70× is 98 BPM, at 0.80× it's 112, and at 0.90× it's 126. Set your metronome to match and you can practice the passage with or without the recording. New to practicing with a click? See How to Use a Metronome (Beginner Guide).
Step 3: Slow the clip down with a music speed changer
Go to the Speed Changer and drop in your clip. A Tempo Control panel appears with a single Tempo slider running from 0.50× (Slower) to 2.00× (Faster) in 0.05 steps, with 1.00× as the original speed.
Drag it to your starting tempo and press play. You can move the slider while the clip is playing and hear the change right away, which makes it easy to find the speed where you can play the passage cleanly but still have to concentrate.
When it's set, pick a format and press Export. WAV is lossless; MP3 is smaller if you're putting it on your phone. Name the file with the tempo (solo-070.wav) so you don't lose track.
Picking a starting tempo
There's no correct number. A reasonable rule: start at the fastest speed where you can play the passage without mistakes. For many players that lands somewhere around 0.60×–0.75×. If you're still missing notes, go slower. Practicing an error at any speed just practices the error.
Going below about 0.60× makes stretching artifacts easier to hear, a slight smearing on drums and fast notes. It still works for learning note by note at 0.50×, but expect it to sound a bit rough.
Step 4: Slow down music to practice, then step it up
This is the core of the routine. Export a few versions of the same clip:
| Stage | Tempo | Goal |
|---|---|---|
| 1 | 0.70× | Get the notes and fingering right |
| 2 | 0.80× | Play it cleanly several times in a row |
| 3 | 0.90× | Play it relaxed, not just accurately |
| 4 | 1.00× | Play it at full speed with the record |
Load each one into your player, set it to repeat, and play along. Move to the next stage only when the current one feels easy, not when you've scraped through once. Some days you'll go back a step. That's normal.
You can use smaller jumps (0.05 at a time) for a really stubborn run, or bigger ones for a passage that's nearly there. The slider steps in 0.05, so 0.75× and 0.85× are available too.
Step 5: Put it back into the song
Once the clip is solid at 1.00×, play the full track from a little before the passage. Getting into and out of a section is a skill of its own, and the clip alone won't teach it. If the transition trips you up, go back to the Audio Cutter, cut a slightly longer clip that includes the lead-in, and run it through the stages again.
Optional: make the backing track easier to hear
Hear your part more clearly, or remove it
A busy mix can bury the part you're learning. The Stem Splitter separates a song into four stems (vocals, drums, bass, and other) so you can solo the bass line you're learning or mute it and play it yourself. Do this on the original clip before slowing it down. It runs an AI model in your browser: the first time, the model downloads to your device, and the separation then runs on your own computer, so a longer song takes a while.
For singers or anyone who wants just the instruments, the same idea applies to vocals. How to practice singing with backing tracks walks through that workflow.
Change the key for your instrument or tuning
If the recording is in a key that doesn't suit your instrument, say a guitarist tuned a half step down, or a horn player reading in a different key, shift it with the Pitch Changer. How to transpose a song to a new key explains how many semitones to move. Pitch and tempo are separate tools here, so you can change one without the other. How pitch, speed, and duration are related explains why they're normally linked.
Troubleshooting
The slowed clip sounds smeared or watery. That's time-stretching at low ratios. Raise the tempo a notch, or accept it at the earliest stage. Starting from a WAV or high-bitrate file helps a little.
I can't loop inside the Speed Changer. Correct, it doesn't have a loop function. Cut the passage first with the Audio Cutter, export it, and loop the file in your media player.
The recording sounds out of tune with my instrument. The Speed Changer keeps the original pitch, so the mismatch is in the recording or your tuning. Some older recordings sit slightly off standard pitch. Tune to the track, or nudge it with the Pitch Changer.
More guides like this are in the how-to section of Learn.
Frequently asked questions
Does slowing down music change the pitch? Not with the Speed Changer. It slows the tempo and shifts the pitch back by the opposite amount, so the song stays in its original key at any setting from 0.50× to 2.00×. A plain playback-rate change without pitch correction would make it lower and deeper.
What speed should I practice a hard passage at? Start at the fastest tempo where you can play it without mistakes, often somewhere around 0.60× to 0.75×. Then step up in small stages, for example 0.80×, 0.90×, and 1.00×, moving on only when the current speed feels easy.
Can I loop a section in the Speed Changer? No. The Speed Changer plays and exports the whole file. To loop a passage, cut it out first with the Audio Cutter, slow the clip down, export it, and set your media player to repeat it.
How slow can I go? The slowest setting is 0.50×, which is half speed. It works for learning notes one at a time, but very low settings make stretching artifacts easier to hear, especially on drums and fast runs.
Is my audio uploaded anywhere? No. The Speed Changer, Audio Cutter, and the other tools process audio inside your browser. Your audio never leaves your device, and there's no account or signup.