In the year 1991 a significant number of M-Base participants labelled as "M-Base Collective" recorded the CD "Anatomy of a Groove." Most of them previously contributed to CDs by alto-saxophonist Steve Coleman whose creativity has been a pivotal factor in that movement, although he refused to be called its leader or founder. Coleman and his friend Greg Osby, who plays alto saxophone in a related style, together led the group “Strata Institute” which recorded two CDs (the second with tenor saxophonist Von Freeman as a further leader). Under the name of Osby, a number of CDs with a specific character have been released starting in 1987 which also coined the perception of "M-Base" jazz. Tenor saxophonist and flutist Gary Thomas admittedly didn't take part in the M-Base initiative, but joined them, and there were similarities in his way of playing. He can be heard on recordings of Coleman und Osby and his own CDs are also labelled as "M-Base-style." All three saxophonists contributed to the CD "Jump World" by singer Cassandra Wilson.