Boss DB-90 Digital MetronomePractice in style with the flagship of the Dr. Beat Metronome line. The new DB 90 is loaded with quality sounds and drum patterns to make your practice sessions less mundane and more musical. There's a Rhythm Coach function with an onboard mic, a reference tone function for tuning, an Instrument input, MIDI input, and other handy tools to make learning fun and effective. The Note Mixing function allows you to instantly create a variety of beats by