On two consecutive Saturdays, the courtyard at the Hammer Museum will be quite the spectacle of minimalist music (not an oxymoron in this case). Members of The Industry, LA's experimental opera company, will perform Terry Riley's "In C," a hypnotic, semi-spontaneous piece as airsocket dancers (like the ones outside of car dealerships) flail around. To give you an idea of what makes this an installation: The sheet music for "In C" is the same for all performers, and it consists only of a series of patterns of notes. Musicians play through the patterns as slowly or as quickly as they want, staying in time with the beat. The result is a many-layered and ever unique musical performance. This one is estimated to take four hours, so spend the afternoon meandering around the museum and taking in the music.