Vocalist Clarence Fountain is ill with pneumonia, so the Blind Boys of Alabama reshuffle, bringing drummer Ricky McKinnie to the front of the stage. Backing vocalist and guitarist George Scott is absent, too, so bass player Jimmy Carter takes care of all the gentlemanly introductions, name-checking the band's "cee-dees" at every opportunity. His extemporising adds an almost avant-garde texture to the rich vocal mix.

This is a tight performing outfit, with musical director Joey Williams supplying guitar licks and full-blooded falsetto: the younger guys blend seamlessly with the founders' distinctive sound, especially on the a cappella numbers. A rousing version of People Get Ready evokes a whole era of gospel-driven R&B, building slowly from bare electric guitar figures into a wall of sound.

Most of us are on our feet by the time they steam into Last Month of the Year, from their new Christmas "cee-dee", Go Tell It on the Mountain. The song "both asks and answers the question, 'When was Jesus born?'" explains Carter. At the rear of the stage, like hulking nightmare creatures imagined by Francis Bacon or Max Ernst, the one-eyed spotlight mounts swivel and blink - inadvertent but creepy symbols of the moral void against which the Blind Boys pit their righteous tones.

An hour later, deep in the dark stone crypt below St Giles's church in south-east London, Tomorrow's Warriors make a similarly spiritual statement with King David's Dance, an ambitious jazz suite with changing feels and tempos that bring to the fore the alto sax of Nathaniel Facey. And if the extended blowing tests the musicians' capabilities, their tight ensemble work and collective confidence are evidence of the merits of hard work and regular gigs. Each member of the band - with Neil Charles (bass), Shaney Forbes (drums) and Jay Phelps (trumpet) - played well on originals such as Magnolia, and the easy, free-bop rapport between Facey and pianist Gwilym Watkins was a pleasure to hear in the tiny club.