Apple is shipping iOS/iPadOS 15.5 Developer Preview Beta 2 update (Internal version 19F5057e) to iPhone and iPad users today, two weeks after its last release.
IOS 15.5 and iPadOS 15.5 are minor updates to previous versions of iOS 15, and the changes are limited. Apple is likely to release Apple Music Classical apps (mentioned) sometime in the near future. Apple is using the iOS 15.5 update to lay the groundwork for a feature that will allow “Reader” App developers to add links to external websites to register and manage accounts outside the App Store.
Apple Pay Cash also has some minor changes, adding request and send options, and Apple is making some changes to the iTunes Pass that used to be available in the Wallet app.