Electronic tuning aids can be purchased from Lark in the Morning, which
also carries loads of musical instruments, music, musical paraphernalia,
and even mechanical instruments - an imported organ taking punched rolls.

You can browse the catalog on-line at:  http://
www.mhs.mendocino.k12.ca.us/MenComNet/Business/Retail/Larknet/larkhp.html

regards,
Larry Smith