# How to Change the Tempo of a Song

> How to change the tempo of a song without changing its pitch — using time-stretching in a DAW or editor, plus how to find the original BPM first so you stretch accurately.

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# How to Change the Tempo of a Song

Published 4 September 2026, 09:00 UTC · updated 12 August 2026, 21:30 UTC · by Loopin

Slowing down a track to learn a part, or speeding one up to fit a set, is easy once you know the tools — and the one rule that keeps it from sounding terrible: change the tempo without dragging the pitch with it.

## Tempo and pitch used to be linked

On a record or tape, speed and pitch are physically tied: spin it faster and everything goes up in pitch like a chipmunk; slower and it drops and drags. For decades that was the only way to change tempo, which is why old DJ pitch faders shifted the key too.

Modern software breaks that link with **time-stretching**, which changes the tempo while holding the pitch steady (or changes pitch while holding tempo). That’s what lets you slow a solo to half speed to learn it, without it dropping an octave and going muddy.

## How to change tempo in a DAW or editor

In a DAW (Ableton, Logic, FL Studio and the rest), import the audio, tell the software the file’s original BPM, then change the project tempo — the clip time-stretches to follow, pitch intact. Choose a stretch algorithm suited to the material (one optimised for complex/full mixes versus one for monophonic instruments) for the cleanest result.

If you don’t have a DAW, free audio editors and dedicated ‘tempo changer’ tools offer a time-stretch or ‘change speed without pitch’ option that does the same job for a quick slow-down or speed-up. Either way, the more accurately you tell it the original tempo, the cleaner the stretch.

## Find the original BPM first

Every clean tempo change starts with knowing the song’s *current* BPM — stretching from the wrong starting number leaves you off-grid and warbly. So before you touch the tempo, drop the track into the [free key & BPM finder](/key-bpm-finder) to read its exact BPM (and key) in seconds, then stretch from that accurate baseline.

Knowing the key matters too, because aggressive stretching can subtly affect tone, and you may want to confirm the pitch hasn’t drifted. The same [key & BPM finder](/key-bpm-finder) gives you the key too, so if you’re also planning to shift pitch deliberately you know exactly where you’re starting from — see [how to find the key of a song](/blog/how-to-find-the-key-of-a-song) for more.

## Stretch within sensible limits

Time-stretching has limits. Small changes (within roughly ±10-15%) usually sound transparent; push much further and you start hearing artefacts — smearing, a metallic or ‘underwater’ quality, especially on busy full mixes. For big tempo moves, expect to accept some of that, or stretch stems individually for a cleaner result.

When you’ve made the change, listen on a couple of systems before committing. And if the stretched track is part of a finished production — a remix or edit — run it through a clean [master](/mastering) at the end so any small artefacts are minimised and the final file sits at a competitive, consistent loudness.

## Frequently asked questions

### How do I change a song's tempo without changing its pitch?

Use time-stretching, available in any DAW and in free audio editors. Set the file's original BPM, then change the project tempo and the audio stretches to match while holding pitch steady. Pick a stretch algorithm suited to the material for the cleanest result.

### Why does my slowed-down song sound warbly?

Either the time-stretch algorithm isn't suited to the material, or you've stretched too far. Changes within about plus or minus 10-15% sound cleanest; large moves introduce smearing and metallic artefacts, especially on full mixes.

### Do I need to know the original BPM to change tempo?

Yes, for a clean result. Stretching from the wrong starting BPM leaves the audio off-grid. Use a key & BPM finder to read the exact original tempo first, then stretch from that accurate baseline.

## Related reads

- [How to find the key of a song](/blog/how-to-find-the-key-of-a-song)
- [How to find the BPM of a song](/blog/how-to-find-the-bpm-of-a-song)
- [Free key & BPM finder](/key-bpm-finder)

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Source: https://onloopin.com/blog/how-to-change-the-tempo-of-a-song