JAMESTOWN, N.Y. (AP) _ Martha Schlamme, a cabaret singer and Broadway performer, died at a hospital here two months after collapsing during a performance at the nearby Chatauqua Institution. She was 57.

Miss Schlamme died Sunday. Mary Weedon, community relations director at Woman's Christian Association Hospital, said Miss Schlamme never regained consciousness after suffering a stroke on stage Aug. 7.

She was performing before an audience of 3,000 at the Chautauqua Amphitheater when she stepped back to the piano, said ''I'm fainting,'' and collapsed.

Miss Schlamme, born in Vienna, sang songs in 12 languages. She began her career in Europe where she learned country folk songs and theatrical songs by Bertolt Brecht and Kurt Weill.

About 20 years ago she performed ''The World of Kurt Weill in Song'' off- Broadway and had toured North America and Europe, singing Weill songs. She performed a Weill cabaret on Broadway in 1980.

Services for Miss Schlamme will be held Wednesday in Mahnattan, according to spokesman Phil Zimmer of the Chautauqua Institution, a resort that features lectures and concerts.