Where to purchase the music ?

You choose where you get your music. However we suggest you discuss this topic with the head of studio you're teaching at. Just so you're legally on the safe site.

However if you are looking for a suggestion we highly recommend the streaming service 

We highly recommend Spotify if you're looking for a convenient service for testing your class profiles at home. A premium membership enables you to experience a whole new level of listening to music at home.

As previously mentioned you can use any source, e.g. your own iTunes collection. T

The sky is the limit!