Performance Magic
A Minor Hermetic Virtue allowing the magus to disguse the casting of spells as the application of some mundane Ability such as Music, Hunt, or so on. Performance Magic (Music) is known as Sorcerous Music, and has several advantages (including a greatly increased Voice Range).
The virtue allows access to the new Spell Duration, Performance.
References
Performance Magic was first described in TMRE 29-30. An abbreviated treatment is provided in HoHS 58.