With the RingerToggle add-on for CCSupport, jailbreakers can add a ringer/silent toggle to Control Center just like Action Button-equipped iPhones can.

The latest point of contention between Spotify and Apple is the iPhone's physical volume buttons, which no longer work with Spotify Connect.

You can use a new and free jailbreak tweak called MutePlay to prevent incoming notification sounds from disrupting your music playback.