Post Bop refers to a diverse set of jazz innovations which expanded the harmonic and rhythmic language of Bebop and Hard Bop while retaining the swinging pulse and basic small-combo format. In the early 1960s, great changes in jazz took place. Pianist Bill Evans's inventive trio crafted an impressionistic approach to swing which made the trio appear almost telepathic. John Coltrane's famed quartet built towering edifices of harmonic invention over two-chord vamps and classic Bop chord changes. Miles Davis formed a new quintet which combined the rhythmic ideas from Evans with the influences of Free Jazz. In the 1970s, saxophonist Joe Henderson and trumpeter Woody Shaw created innovative music which bridged Hard Bop and Avant-Garde Jazz. Post Bop continues to develop today, with the work of such luminaries as Kenny Garrett, Mulgrew Miller, Wallace Roney, Bill Stewart, Geri Allen, and many other modern masters.