The group unamimously made the decision last week, with the 26 year-old bassist starting immediately. A fan website reported that the band made the announcement at the Fox Theatre in Boulder last week, and that Tad had played several California gigs with the band earlier in the week.

Blues Traveler has had a tough summer: first, vocalist John Popper's angioplasty, then the death of 31 year-old Sheehan, the band's founding bassist and a musician of wide-ranging abilities who overdosed in New Orleans on Aug. 20.

''As painful as the situation has been for us, having the opportunity to play with a great musician and my brother makes me excited about the future,'' said guitarist Chan Kinchla.

He and his brother Tad grew up jamming together in Princeton, N.J. According to Blues Traveler's publicist, Tad went to Brown University in Providence, R.I., playing in Dowdy Smack, a hard funk-rock outfit. The group released an album, ''Ain't You Delicious,'' and then Tad moved on work with the band Smithaus in informal jam sessions.

Before deciding on Tad, Blues Traveler reportedly considered Dave Ares (John Popper Band), Oteil Burbridge (Frogwings), Mark White (Spin Doctors) and Steve Manning (Stolen Ogre).

Tad will join the group in the studio in Jan., 2000 to work on a follow-up to 1997's ''Straight On Till Morning'' (Universal/A&M).