Class attendance policies, in both the University at large and the Music Department, are established by the individual faculty members. Each professor may have a slightly different policy, so if it is not printed in the class syllabus, always inquire about it.
Ensemble attendance is different from class attendance. Members of ensembles are expected to be present at ALL rehearsals and performances. Absences from ensemble rehearsals, even for apparently serious reasons, MUST be excused by the ensemble director.