Add a premium subscription of say $50/month for professional dance/music/gym instructors. As a instructor i should be able to give out a link during the class which enables all students (not even spotify premium subscribers) to join the group class from spotify on their phones. Only i can control what is being played, pause/rewind/forward etc.
It can also be priced as $x/student-hour. So a class of 1 hr with 20 student will use credits worth of 20 student-hours.
This can be very useful when teaching dance classes where the song should be synchronized amongst all students, OR in virtual concerts where again the music must be synchronized.