TuneSlider

TuneSlider changes a song's speed without changing its pitch, and its pitch without changing its speed — down to the cent. Built for practicing, transcribing, and slowing down the hard parts. No subscription, no account, no ads.

THREE DIALS, ONE JOB EACH
Speed, pitch, and fine tune are always independent, and always color-coded the same way everywhere in the app, so you never lose track of which one you're touching.

• Speed — 25%–200% of the original tempo in 1% steps. Pure time-stretch: the pitch never drifts, even at half speed.
• Pitch — ±6 semitones, a full octave of transposition, in whole-step jumps, without ever touching the tempo.
• Fine tune — ±50 cents around whichever semitone you've picked, enough resolution to correct a recording that's just a hair off.

BUILT FOR REPEAT PRACTICE
Real library features, not just a single-file player.

• Per-song memory — speed, pitch, and fine-tune are saved per song and restored automatically the next time you open it, across app relaunches.
• Favorites & playlists — heart a song to favorite it, or build named playlists: reorder, rename, and organize the pieces you're actively working on.
• Play All & full transport — queue an entire playlist and auto-advance through it, with back / rewind 15s / play-pause / forward 15s / next, on-screen and from the lock screen.
• Keeps playing, locked or backgrounded — full lock-screen and Control Center transport controls, and playback survives the screen locking or another app opening.

SEE THE MUSIC, NOT JUST HEAR IT
Three full-screen visualizers, each driven by the actual live, post-speed/pitch audio, not a canned animation:

• Waveform — raw time-domain trace
• Spectrum — FFT frequency bars
• Pulse — radial burst, by loudness

NOTHING TO SIGN IN TO. NOTHING TO SEND ANYWHERE.
TuneSlider has no account, no analytics, and no ads. Every song, setting, playlist, and favorite lives only in local storage on your device — the developer never sees any of it.