In the decade since he left Seattle, former Screaming Trees drummer Barrett Martin has covered a lot of musical ground, doing the L.A. studio thing, studying percussion traditions around the world, and keeping up Tuatara, the cinematic-rock band with R.E.M. guitarists Peter Buck and Scott McCaughey. All of these strainsalong with Martins jazz training at Western Washington Ucome together in this new quintet, formed when Martin moved back home a few months ago. With some of the shrewdest progressive-groove players in townincluding trumpeter Dave Carter, ubiquitous Joe Doria on keys, and fat-toned Brett Joseph on saxthis loose collective mixes funk, Afro-beat, Afro-Latin and a deep swing. Just two gigs in, AfterMath definitely adds up, and their first-Saturday shows at ToST are going to be a highlight of the new-jazz month. Theyll be joined this time by the Nigerian-British singer Adama (a sometime collaborator with Tuatara), the local Senegalese drum master Thione Diop, the Circle of Fire dance crew, and who knows who else.