Changing your streaming quality for online listening is easy. (Please note - if you’re looking to change the quality of your downloads, that’s a different setting.)
On Android, tap the Menu button on the top left-hand side of your screen, go to Settings > Streaming Quality > select the option you’d like.
On iOS, go to your My Music tab (bottom right corner), tap on the Settings wheel in the top left-hand corner > Streaming Quality > select the option you’d like.