I understand. San Francisco supports the arts. It's noble. But, like anything, it can be taken too far. Isn't this sort of thing exactly the definition of "disturbing the peace"? If this music school was in the middle of a cornfield, with no others around, this activity would be fine. But they are not. They are in the middle of a very densely populated city. Why doesn't the City government care about this? They don't have to "just do something", investigate it, and see if the complaint has merit! See if the music school is violating building codes. See if they have soundproofing. Do a thorough, efficient assessment. You know, regulate, like we pay you to.