On my Mac I can see the minutes of each song (on the far right) but on my IPhone I can't see it which is a problem when teaching fitness classes. I want to see the total length of time for a playlist and each song.
Currently it's not possible to view the running time of a track on iOS mobile devices without tapping it to play.
However, if you tap the bottom to bring up the Now Playing view, you can see the length of the track that's playing. You should also be able to see this in lock screen mode. Check out the steps under Mobile and Tablet at this link for more info.