Perfect Tempo slows down any song in Apple Music’s cloud


Change the tempo of any song in Apple Music.
Change the tempo of any song in Apple Music.
Photo: Charlie Sorrel/Cult of Mac

Perfect Tempo lets you speed up or slow down any song in Apple Music, so you can learn how to play it. Unlike every other app that does this, Perfect Tempo works on any song on the Apple Music service, not just purchased and/or downloaded songs. It also has a great, easy-to-use design, which is way better than the utilitarian drop-down lists of many other apps.

Perfect Tempo and Apple Music’s entire streaming catalog

Search and use any song in Apple Music, or your own library.
Search and use any song in Apple Music, or your own library.
Photo: Cult of Mac

There are plenty of slow-downer apps for musicians on iOS, bust usually they can only be used with songs that you have purchased, or that you have stored somewhere on your device, outside the Music app. I usually buy a song when I want to learn it, but the apps I use are painful when it comes to song selection and loading.

Perfect Tempo is laid out more like a music-player app, with access to your entire library in the left column. You can browse by Artist, Album, and playlist. Seeing as I already have a playlist named “Learn,” I totally dig this option.

Playlists and search

You can also search across Apple’s entire Apple Music catalog, and play a song from there. Any songs you load up are remembered, so you can easily flip back to a previous one. This is a big improvement over the otherwise fantastic AudioStretch, which forces you to manually add a song, every single time.

Capo, another slow-downer and analysis app, has a library of previously-used songs, but ever since a redesign put all the most important controls into popover menus I’ve found it unusable.

Just Press Record

The Perfect Tempo developer also makes my favorite iOS voice-memo and recording app, Just Press Record. And Perfect Tempo even has a section in the source column to browse your Just Press Record recordings. Finally, you can also grab songs from the Files app, using the built-in browser. Perfect Temp doesn’t have its own folder in Files, but you can grab music files from anywhere.

Slow down and loop

Slide to slow down, tap to start looping.
Slide to slow down, tap to start looping.
Photo: Cult of Mac

The slowing down is done by swiping on the dial under the album art. The slowing-down algorithm is excellent, without any bad artifacts or distortion. It only slows down to 50% of the original speed, whereas AudioStretch can go right down to 0.01%. But that’s probably not the point. I’ll keep using AudioStretch, with its quick gestures and shortcuts, its on-screen waveform, and its place markers, because it really is a high-end power app.

Perfect Tempo is simpler, and just fine for quickly transcribing a tricky section.

The app also lets you loop a section. To access this tool tap the Loop button twice, until it reads “section.” Then just use the buttons to set the start and end points, and press play.

Again, it’s not as powerful as AudioStretch, which has a draggable waveform to make loop points easy to set. But it’s more than good enough.

Perfect Tempo is $5, which is a bargain already, but which will also pay for itself as soon as you start using it, and not buying songs.

Perfect Tempo

Price: $4.99

Download: Perfect Tempo from the App Store (iOS)