The desire to prevent former bandmates from trading on past rock and roll glory is driving two similar federal trademark cases, with current members of the bands Boston, and, separately, the J. Geils Band, trading bitter accusations with former members about who can claim the names.The cases, in federal court in Boston, illustrate the disputes that arise when band members regroup and launch new tours 20 or 30 years after a band’s heydey. These fights can be highly emotional and involve long-nursed grudges, say attorneys who have represented parties in similar litigation.

“This may be driving [the litigation] more than dollars and cents,” said Ben McLane, an entertainment attorney at McLane & Wong in North Hollywood, Calif., whose practice focuses primarily on the music business. “It’s very common and it happens a lot more with these famous groups than with newer groups.”