MusicKit is an official Apple API that allows developers to construct programs with access to Apple Music, such as third-party clients.
For some inexplicable reason, Apple disabled the option for these applications to alter playback speed—however, this capability will be restored with iOS 15.5.
Multiple developers have protested to Apple since this API was deleted in iOS 15.4. An Apple engineer acknowledged at the time that the firm was “monitoring this problem internally,” but no additional information was provided. Fortunately, it seems that developers may now utilize this API again.
As a consequence, the API for allowing Apple Music applications to modify playback speed has been restored in the fourth beta of iOS 15.5, which is now accessible for developers.
We re-evaluated our prior decision to disallow altering the playing rate for Apple Music subscription content in third-party apps, and we determined that we could safely restore that capability, exactly as we did before the release of iOS 15.4. As a result, this problem has been resolved in iOS 15.5 beta 4.
It’s unknown what prompted Apple to stop this function, but given that the company’s engineer used the term “safely” to characterize the problem, it’s possible that the feature was removed owing to a flaw.
Developers will, of course, need to update their applications to guarantee that the functionality works following the official release of iOS 15.5.