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 twentieth of 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.

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.

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