The Louisiana Cajun band Beausoleil, which began the fourth annual Blue Bayou Music Festival at Prince George's County Equestrian Center Saturday afternoon, played three rousing two-step numbers, took a half-hour rain break and played two more songs before turning the show over to the Tom Principato Band. But that Northern Virginia blues-rock quartet hadn't even finished one song when a thunderstorm exploded onto the site, ripping the tarp off the stage and sending everyone scurrying for cover.

The festival reconvened Sunday with a revamped lineup that allowed Principato a second crack (and he took full advantage). Joining him were rockabilly guitarist Lonnie Mack, Cajun fiddler Dewey Balfa, boogie-woogie pianist Marcia Ball, Cajun-rock accordionist Wayne Toups, soul shouter Solomon Burke and Rock and Roll Hall of Famer Carl Perkins.

Beausoleil, Principato, Mack, Ball and Toups all play in this area regularly, and at the festival they put on their usual fine shows. Balfa's set was an encouraging sign for the future of traditional, acoustic Cajun music, for he introduced three promising youngsters: accordionist Steve Riley (who also leads one of Louisiana's finest Cajun bands), second fiddler Peter Schwartz (son of folk legend Tracy Schwartz, who was playing guitar) and triangle player Tina Balfa (Dewey's daughter). The two generations blended sympathetically to breathe fresh life into the old French waltzes and two-steps. Later Riley and Tina Balfa were out front dancing to the harder, electrified Cajun-rock of Wayne Toups & the ZydeCajuns.

Headlining the festival was Perkins, who came out in a pink shirt and blue suede boots, ready to rock. Rather than wasting his show on other people's hits -- as he has done so often in the past -- he dug into his own songbook for such gems as "Dixie Fried," "Put Your Cat Clothes On" and "Boppin' the Blues." Backed by his sons -- bassist Stan and drummer Greg -- Perkins made his old songs sound lean and fast.

The festival's highlight was an all-too-rare East Coast appearance by "the King of Rock and Soul," Solomon Burke. The rotund ordained minister took the stage in a fur-edged, gold-sequin, floor-length cape, which he discarded to reveal a cream tux with one white glove under his left epaulet. Tossing roses to the crowd as it surged toward the stage, Burke sang his classic early-'60s soul hits such as "If You Need Me," "Just Out of Reach" and "Everybody Needs Somebody to Love" in a powerful tenor that purred one moment and roared the next.

A consummate performer, Burke mimed the telephone call in "He'll Have to Go," and conducted his superb Southern soul band with the body language of hip-shakes and punches. When he started stutter- singing his biggest hit, "Cr-cr-cr-cr-cry to Me," he produced a moment D.C. soul fans have been waiting years to experience.