Boss TU-80 Guitar Tuner and Metronome The reliable Boss TU-80 Tuner & Metronome includes a handy, built-in metronome with 7 rhythms and 10 beats, plus a cool animated LCD display. Multiple features and an ultrawide tuning range of almost 8 octaves make it easy to get the precise tuning you need. The TU-80 supports chromatic tuning, 7-string guitars, and 6-string basses. Accu-Pitch function sounds a tone when pitch is correct, a Reference Tone Play function makes it easy to verify tuning by ear, and it tunes down to 5 flats. The ultrathin body slides easily into a guitar case, gig bag, backpack, or pocket.