Accompanist: Music Slow Downer

Accompanist is a real-time music slow downer and speed changer. Put a giant on-screen knob in front of any song you own and pull the tempo down to learn it — or push it up to performance speed — with the pitch locked to the original key. Built for dancers and teachers, and for any musician learning a song by ear. All in real time, all on your device.

CHANGE SPEED ANY WAY YOU LIKE • A big rotary knob — drag in a circle. • A slider with a clear 1× marker. • Plus / minus buttons that nudge by 0.01×. • A type-in field for an exact speed. • Quick presets across your range. • Set your own range and the value in the middle — from a gentle 0.9–1.1× to a wide 0.25–3×.

KEEP THE PITCH — OR LET IT MOVE One toggle decides how the music responds: • ON — tempo changes, pitch stays in the original key. Perfect for drilling choreography slowly, or learning a riff note for note. • OFF — the classic record-speed effect. Set the speed back to exactly 1× and the song returns to its original sound.

SEE THE LOUD AND SOFT The timeline is a volume waveform — see the build-ups and drops, with your loop and markers on it.

LOOP & DRILL A TRICKY SECTION • Mark A and B on the timeline and the music loops that section on repeat — drill a hard 8-count, or a fast solo, as slow as you like. • The loop region shows right on the progress bar, and clears with one tap. • Speed Trainer — each time the loop comes round, the tempo nudges up, so you start slow and build up to full speed automatically.

KEEP THE BEAT • Tap along to set the BPM, then get a "5, 6, 7, 8" count-in before the music starts. • Turn on the metronome to click along at your tempo while you teach. • Drop section markers (Intro, Chorus, the lift) and jump straight to any part of a song.

A PROFILE FOR EVERY DANCER (PRO) • Record your speed and volume changes as a song plays, then save them under a dancer's name. • Press play and the app drives the speed and volume for you — hands-free — so you can watch the floor. • See the whole routine on a speed chart and a volume chart. • Share a profile with another dancer; it reattaches to the same song on their device. • Profiles back up to iCloud and restore on your other devices.

VOLUME, FADES, AND BOOST • Per-song volume, independent of your phone's volume — with a tap at 100%. • Boost above 100% to lift a quiet recording; set your own volume range. • Smooth fade-in and fade-out.

EXPORT YOUR ADJUSTED SONG (PRO) Save the music at your chosen speed — following your saved profile's changing speed and volume — as an audio file. Pick the format (match the original, M4A, or WAV), see the size before you export, then play it anywhere.

ORGANIZE INTO FOLDERS • Add a whole folder and the app keeps its subfolder structure — perfect for a class (Warm Up / Barre / Centre). • Make your own folders, open them, and play straight through a folder. • With Accompanist Pro, sync folders across iPhone and iPad over iCloud — switch on "Sync music" to carry a folder's songs too. • Share a whole folder — songs and dancer profiles included — with another teacher (Pro); they tap your link to import it. • Import from Files (iCloud Drive, file servers), or from Google Drive / Dropbox via Share ▸ Accompanist. • Pull the audio out of a video (Pro). Select several songs to remove at once. • Keep playing in the background and over AirPlay.

MAKE IT YOURS Pick a colour theme — Midnight, Rose, Ocean, Sunset, Forest, or Graphite — to restyle the knob, bars, and background.

ON YOUR APPLE WATCH Control the music from your wrist — play/pause, speed, volume, and skip — so you can run the class without reaching for your phone.

iPHONE AND iPAD A clean, full-screen layout on both.

PRIVATE BY DESIGN No ads. No accounts. No tracking. Your audio and profiles stay on your device and in your private iCloud.

Accompanist Pro is available as a monthly or yearly subscription.