Music Speed Changer supports two types of playable tracks, unlocked and locked.
Unlocked tracks are DRM (Digital Rights Management) free. All features of the app are available with maximum quality when playing these tracks.
Unlocked tracks are:
- Songs purchased and downloaded through the iTunes Store app.
- MP3, M4A or other audio files that you have manually added to your Apple Music library and downloaded on your iPhone or iPad.
- MP3, M4A or other audio files imported through the Files app that are listed in the Files section of Music Speed Changer. See here for more info
- Podcasts added to your library and downloaded in the Apple Podcasts app on your iPhone or iPad.
Locked tracks are protected by DRM and not all of the features of the app are supported.
Locked tracks are songs that you have added to your Apple Music library through the Apple Music app. These can include any of the 90 millions available in the Apple Music catalog.
Locked tracks are limited in the following ways:
- The only available effect is changing the playback speed without pitch shift, i.e., the Tempo control**. The quality of this effect is inferior to that used on unlocked tracks.
- Only three of the four playback modes are supported. Pause at the end of each track mode is not supported. See here for more info
- Shuffle mode is currently not supported.
- Operations on the playing queue such as inserting, moving or deleting tracks are not currently supported.
- The waveform view is a placeholder and doesn't match the audio.
- Saving the edited audio to a new file is not supported.
- Looping is not seamless.
- You must be online to play these tracks, even if you have downloaded them.
** In iOS 15.4 Apple briefly removed the ability to change the playback speed of locked tracks. This restriction has been removed in iOS 15.5.
Purchasing an Unlocked Version
You can easily purchase an unlocked version of a locked track through Music Speed Changer. Click on the lock or cloud icon next to each locked track to be directed to the purchase page on the iTunes Store. After purchase and download, the track will be available in the Unlocked Songs section of Music Speed Changer.
Music Speed Changer will play locked tracks with Dolby Atmos if it is available for the track in Apple Music.