Crescendo is the music instrument store in the mall that several students of CHS work at. The notable employees are Vinyl Scratch (@EqG_DJpon3), Octavia Melody ( @), Sunset Shimmer (@), and Rimshot (@). It's open during mall hours, however, it's closed on Sundays.
If you need an instrument, you can find it at Crescendo. Either in stock, or from one of their catalogs. It's located on the second floor of the mall, occupying a large space near one of the anchor stores. The instruments line the walls, and the aisles hold the accessories, strings, replacement pieces, music books, etc.