It often depends on the type of art that the teacher was looking for. For example, if a ceramics teacher was looking for a coil pot, often times they will just hand out a rubric. Typically the requirements on art rubrics are loose- otherwise everybody's work would end up looking identical. For example, one requirement could just be "a couple rows of different coil designs" for a coil pot for full points on that assignment. Art teachers also grade based on a self-reflection form students may fill out. For more abstract pieces, the teacher might just grade based on why the student designed their artwork like that.
Hope that helped you.
Depends on the music. The most popular ones include timpani, triangle, cymbals, snare drum, bass drum
