Michael Mantler was born in 1943 in Vienna, Austria, where he studied trumpet and musicology at the Academy of Music and Vienna University. In 1962 he went to the USA to continue his studies at the Berklee School of Music in Boston.
He moved to New York in 1964 and started playing trumpet with Cecil Taylor and others. During that period he was also involved in the formation of the Jazz Composer's Guild, a collective of musicians and composers, struggling for better working conditions and opportunities to present their new music without compromise. Together with Carla Bley he formed a large jazz orchestra to perform new compositions, resulting in their first recording Communication.
After the Guild discontinued its activities, he toured Europe twice during 1965/66 with the Jazz Realities Quintet, featuring Steve Lacy and Carla Bley