Clear downloads: Erases your downloads from YouTube Music on your current device.You can limit the number of downloads based on your storage needs and allow the app to download up to 200 recently played songs. Smart downloads: Toggling this on will allow YouTube Music to automatically download your favorite tunes, based on your listening habits.You can choose between medium (360p), HD (720p), or audio only (if available).
You can choose from low, normal, and high.
These are the various settings down in the Downloads & Storage menu and their functions: You can also view your available storage from this page. Here, you'll be able to change various aspects of your YouTube Music downloads.