As one Titanic survivor recalled, "The way the band kept playing was a noble thing . . . the last I saw of [it], when I was floating out in the sea with my lifebelt on, it was still on deck playing . . . How they ever did it I cannot imagine." British composer Gavin Bryars took this reminiscence, and conjectures as to just what music was heard on deck that night, as the basis for his 1969 conceptual-art piece The Sinking of the Titanic. (Tradition has it the last hymn played was "Nearer My God to Thee," though sources differ.) Bryars' "score" is his pages of research notes about the event. But how do you make a performance out of these notes? The realization planned for Saturday will include improvisations on that hymn and other period music by 30 musicians scattered around the Chapel Performance Space, surrounded by field recordings, electronic processing, video projections, Victrolas playing 78s, and a recitation of the names of the disaster's 1,514 victims. Coordinating this epic collage/happening is composer and contemporary-music patron saint Steve Peters, who's gathered an all-star lineup from Seattle's avant-classical scene to play for three hours, roughly the time the ship took to sink after hitting the iceberg: from 11:40 p.m. April 14, 1912, to 2:20 a.m. April 15, North Atlantic time. In other words, this commemoration of the tragedy takes place one hundred years later to the hour.