Correction Appended

Mark Sandman, the leader of the idiosyncratic Boston rock trio Morphine, died on Saturday during a performance at the Giardini del Principe in Palestrina, near Rome. He was 47.

The cause was a heart attack, according to The Associated Press. Mr. Sandman collapsed in front of several thousand fans during a performance on the second day of a three-day festival that was a stop on the band's two-week European tour.

There were few groups in the rock world like Morphine. Instead of playing guitar, Mr. Sandman played a slide bass with only two strings. He sang in a near-monotone baritone while his band mate Billy Conway played delicate percussion. The third member, Dana Colley, often played two saxophones simultaneously. Despite such a limited palette, the band's songs were memorable, evocative and accessible.

Morphine's slow, smoldering albums often sounded like soundtracks written for pulp-fiction novels, and its concerts reflected Mr. Sandman's devilish, dry humor. The group's music appeared on the soundtrack to many films, including ''Get Shorty,'' ''Spanking the Monkey'' and ''Beautiful Girls.''

Before forming Morphine in the early 1990's, Mr. Sandman was a taxi driver. He also played with the Boston group Treat Her Right, throwing the occasional minimalist pop song into the band's blues-based repertory. Once in Morphine, he was signed to the leading independent label Rykodisc and then to Dreamworks, releasing five albums, including ''Good,'' ''Cure for Pain,'' ''Yes'' and ''Like Swimming.'' Favorite songs among the band's cult, college-aged audience ranged from those with silly lyrics delivered in a deadpan voice to those with Mr. Sandman's more insightful beatnik-style poetry.

Mr. Sandman also formed several bands as side projects, including the more upbeat Hypnosonics, the country Pale Brothers and the sarcastically titled Supergroup, with Chris Ballew of the joke-pop band Presidents of the United States of America.
Mr. Sandman is survived by his parents.

Photo: Mark Sandman (Associated Press)