It’s real annoying when you are listening to music on your iPhone, iPad or iPod touch & suddenly iOS Music App album cover art screensaver appears & occupies whole screen & there is no way to get out of that screen saver & back to Music app.
Actually iOS Music App screen saver starts when you hold your device horizontal accidentally or intentionally.
But there is solution,
Solution: Hold your device i.e. iPhone, iPad, iPod touch vertical & screensaver will disappear. Holding device vertical is way to get rid of scrensaver or album cover art visualisation.
Hope it helps,
Thanks & Regards