Starting at 1.5 hours before the performance one can get student tickets (the person needs to be present and show student ID, doesn't matter Swiss or not). Costs 22 CHF and normally places are very good, somewhere are in Parkett
Starting from Monday 11h at the week before the concert one can get tickets for 20 CHF (link).
For young people until 25 years old, members of For young people until 25 years old, members of klubZ until 29, and students until 30.