Jon Catler is one of the world's leading innovators on microtonal guitar. For many years, Catler's life has been devoted to the exploration of the "notes-between-the-notes," or microtonal music. Specifically, he has devised his own system of tuning based on Just Intonation or the pure intervals of the Harmonic Series. He has redesigned his guitar to allow an unprecedented range of consonance and dissonance, alternating between a 62-note per octave fretted guitar and a fretless. Noted for his work with legendary composer, La Monte Young, Mr. Catler can be heard as featured soloist on the Gramavision double-CD "La Monte Young and the Forever Bad Blues Band." Catler temperament is named for him.