Alfred Music Publishing 97-PT16 Tuner
A cappella singers, quartets, and choral groups will find this battery-operated, tone generating device indispensable. A must when there is no piano or reference instrument nearby---it's even used by American Idol coaches and contestants. The volume is adjustable. The individual note select gets you an immediate tone, and besides all of that, the PT-15 fits right in the palm of your hand!