Pianist/composer Mary Lou Williams' Mass is almost inevitably going to be principally intriguing to two groups of buffs - jazz historians, and scholars of African-American Catholicism. But if you can get past the rather stiff and worthy Swingle-Singers-for-God feeling of some of the choruses, this warrants more than mere academic interest.

Williams was a brilliant player and an original composer and arranger who gave the 1930s Andy Kirk swing band their distinctive sound. Moreover, in 1946, at Carnegie Hall, in tandem with the New York Philharmonic, she was one of the first jazz musicians to have a composition played by a front-rank symphony orchestra.

By the 1960s, via bebop, she had developed her own kind of complex avant-post-bop, a mix of early jazz piano influences, blues, and bold dissonances. In the previous decade, though, Williams had dropped out of music for some years, returning as a devout Catholic. This is the best-known of her three masses, thanks to Alvin Ailey's choreography of it for his Dance Theater.

Some of the music is conceived like 20th-century classical music (the methods of Penderecki surface in the harsh sounds of Lamb of God), some of it is freewheeling gospel and some is the kind of chord-based hard bop that suggests Williams might have been an influence on McCoy Tyner.

The falsetto singing of Carl Hall on Kyrie Eleison makes your hair stand on end, and two simple pieces devoted to Martin Luther King are very haunting. But Roman Catholic ritual, not jazz, is the driving force here - a point that might be worth bearing in mind.