Slow down music without changing the pitch
The heart of learning music by ear: take a recording down to a speed where you can hear every note, while it stays in the original key. SlowBird plays from a quarter speed up to double, with one-tap presets at 50, 65, 75 and 85% for practice, and what you learn slow is exactly what you play at tempo.
Free 7-day trial · macOS 14 or later · Windows 10 or later · £19.99 once, both platforms
How to slow down a song without changing the pitch
- Bring the recording in. Drop an MP3, M4A, AAC, WAV, AIFF, FLAC or CAF file on the window, open an MP4 or MOV video, paste a link, or record whatever your computer is playing.
- Pick a speed. Tap a preset (50, 65, 75 or 85%) or set anything from 25% to 200%. The key stays where it was.
- Loop the hard part. Drag across the waveform and the passage loops seamlessly, with no click at the join.
- Creep back up to tempo. Nudge the speed up a few percent at a time as the passage settles, until you can play it at 100%.
- Come back tomorrow. SlowBird remembers each track’s speed, pitch, loops and notes, so the next session starts where this one stopped.
Why slowed-down music usually sounds bad, and how SlowBird avoids it
Slowed audio quality is the whole game. SlowBird stretches time through Signalsmith Stretch, a modern open-source stretcher chosen for how it treats transients, the attack of each note. A fast bebop line or a picked guitar run at 40% still articulates cleanly instead of smearing into porridge. And at 100% speed with no transposition the stretcher is bypassed entirely, so normal playback is a bit-clean copy.
Pitch is a separate control: transpose in semitones for your instrument, trim by cents for records that were never quite at A=440, and the tempo never moves. Pair it with seamless looping to drill the two bars that keep beating you.
Which speed should you practise at?
Slow enough to hear every note, not just to follow along. Half speed is a good first pass for a fast bebop line or a busy drum fill: every beat takes twice as long, so the rhythm is easy to count. 65 to 75% suits working out phrasing and articulation, and 85% is the last step before playing along at tempo. Save the passage as a note and it is one click from looping at the next session.
Questions
Does slowing a song down change its pitch?
On a record player or a tape machine, yes: half speed drops everything by an octave. SlowBird stretches time instead, so a song slowed to 50% plays in its original key. If you do want a different key, transpose it separately, in semitones or by cents, and the tempo stays put.
How slow can SlowBird play a song?
Down to 25%, a quarter of the original speed, and up to 200%. The presets at 50, 65, 75 and 85% cover most practice.
What can I slow down?
Audio files (MP3, M4A, AAC, WAV, AIFF, FLAC and CAF), MP4 and MOV videos, links you paste, and anything your computer is playing, recorded straight into your library.
Does it work on Windows as well as Mac?
Yes. SlowBird runs on macOS 14 or later and on Windows 10 or later, and a licence covers two computers, Mac or Windows in any mix.
Can I try it for free?
Try SlowBird free for 7 days, no card needed, then buy it once for both platforms: a licence covers two computers, Mac or Windows in any mix.
Free 7-day trial · macOS 14 or later · Windows 10 or later · £19.99 once, both platforms