Grateful Dead fans are attracted to any offshoot of that illustrious rock institution, so Bob Weir's concert at the University of Maryland Ritchie Coliseum last night was essentially a gathering of Dead heads. Weir, the Dead's rhythm guitarist, and his mostly star band, operating as Bobby and the Midnites, reached into a grab bag of rhythms and styles and spent most of the night essaying into familiar territory as if they were intrepid explorers.

The Dead cover similar terrain -- funk, fusion, reggae, electric jug band, blues -- but the Midnites gave it a heftier twist, thanks to drummer Billy Cobham and bassist Alphonso Johnson. Both are veteran, powerhouse players who have submerged their dazzling technique to give this band a snap and a funk bottom that punches Weir's material into life. Johnson in particular, stood out, his booming, elastic bass lines coursing through the hall. Surefingered lead guitarist Bobby Cochran gave into excess only on a gratuitous medium-tempo blues; for the most part his playing was logical, campact, brightly etched and exhilarating.

Weir is immensely likable, an optimist and caretaker of ideals. That excuses a voice that is fervent but fragile and tends to skirt such niceties as pitch and melody. Still, he delivered mostly new material earnestly and with variety.