Belgian saxophonist Michel Mast can often be heard playing tenor on avant-garde jazz and rock albums, and he has been featured on baritone and soprano saxophones as well. Mast began appearing on recordings in the early '80s, as a member of Luc Houtkamp's saxophone quartet Hommage on the group's 1981 eponymous album and also that same year on the FMP release Sib Langis by the Berlin Jazz Workshop Orchestra. In 1984 Mast appeared on the 12" vinyl release Wir Sind Wieder Da! by the Simpletones, an instrumental avant rock group that also included reedman Peter Vermeersch in the lineup. As it turned out, much of Mast's subsequent performing and recording career would be spent in the orbit of composer/bandleader Vermeersch, beginning with the tight and energetic X-Legged Sally, with Mast making significant contributions to the group's punched-up sax-heavy riffage.

Mast appeared on all the XLS albums, beginning with 1991's Slow-Up and ending with 1997's Bereft of a Blissful Union, the latter a joint project of XLS and the Smith Quartet composed as accompaniment (like various other XLS compositions penned by Vermeersch) for a Wim Vandekeybus dance production. After the dissolution of XLS, Vermeersch formed the experimental big band Flat Earth Society, and Mast was one of several XLS members tapped by Vermeersch for the new ensemble. Mast has since been a FES mainstay, included in the lineup for all of the band's releases from 2000's Live at the Beursschouwburg EP through 2013's 13.

Mast is also a member of the Ghent-based Wofo, a smaller outfit ranging in size from quintet to sextet, led by bassist/composer Xavier Verhelst. As the only saxophonist in this often amiable but still uniquely avant group, Mast's contributions as both ensemble member and robust but not overly flashy or histrionic soloist stand out nicely, and Wofo is a fine showcase for his playing (although Vermeersch provides him with numerous moments in the spotlight as a member of the massive FES; in fact, Mast was the last man standing in the 2011 FES production entitled R.I.P., in which the group gradually shrank in size as the bandmembers sequentially "died" and left the stage). In addition, Mast is a member of the Jimmy Giuffre-inspired drummerless trio Laughing Bastards, also featuring guitarist Jan-Sebastiaan DeGeyter and bassist Nils Vermeulen. He has previously performed and/or recorded with the late Steve Lacy and John Tchicai, Dutch saxophonist Dies Le Duc, and Belgian world fusion percussionist Chris Joris. ~ Dave Lynch, Rovi