During these same decades of the 1950's and 1960's, some musicians took jazz in more exploratory directions. The terms free jazz and avant garde are often used to describe these approaches, in which traditional forms, harmony, melody, and rhythm were extended considerably or even abandoned. Saxophonist Ornette Coleman and trumpet player Don Cherry were pioneers of this music through albums such as The Shape Of Jazz To Come and Free Jazz. The former album, as well as several more recorded with a quartet that also include either Scott LaFaro or Charlie Haden on bass and either Billy Higgins or Ed Blackwell on drums, still retains the basic feel of traditional post bop small group jazz, with alternating soloists over a walking bass line and swinging drum beat. This style is sometimes known as freebop. The album Free Jazz was a more cacophonous affair that featured collective improvisation