I have an autoharp and bad hearing...so after years of blowing into a pitchpipe that was NOT perfect, I got a fancy Korg tuner...it has lights, a centering needle, will play the note you want thru about 3+ octaves(in case you have those who MUST hear the note), has adjustable pitch from A338-A446, has AC plug and has input for a clamp-on like has been mentioned...now I can tune in a room full of noodling guitarists and get it right on. Life is MUCH better.