How can I eavesdrop on a student while they are practicing?

Press the Practice mode button.
Press the Play tab from the row of tabs at the bottom of the screen.
Press the number corresponding to where a student is sitting in the classroom, to eavesdrop on that student. You will be able to hear that student's mic and instrument, but they will not be able to hear yours, and they will not be aware that you can hear their instrument or mic. The student keyboard group will be highlighted on your GEC3 unit to indicate that you are eavesdropping on that student.
To end eavesdropping, press the Practice Mode button, or select another student.