Music Stores are a great resource for instrument rentals, purchases, repairs, cleanings, supplies, sheet music, private lessons, etc.
They carry most items on hand but it's a good idea to call in advance to make sure they have what you need.
Music Village http://www.musvil.com
5885 Santa Teresa Blvd, San Jose CA 95123 (408) 629-1812
2971 Union Ave, San Jose CA 95124 (408) 377-2504
Store Hours: Mon - Th 10-8pm Fri 10-6pm Sat 10-5pm
West Valley Music http://www.westvalleymusic.com/
300 W El Camino Real Mountain View, CA 94040 (650) 961-1566
Store Hours: Mon-Sat 10am-7pm
Starving Musician https://starvingmusician.com
3939 Stevens Creek Blvd, Santa Clara CA 95051 (408) 554-9041
Store Hours: Mon-Fri 11-7pm Saturday 11-6pm Sunday 12-5pm
Exploring Music https://exploringmusicusa.com
1608 S De Anza Blvd, San Jose, CA 95129 (408) 517-1177
Store Hours: By Appointment Only
Park Avenue Music https://www.1717parkmusic.com
1717 Park Ave. San Jose, CA 95126 (408) 279-5100
Store Hours: Mon - Fri 10am - 4:30pm