As he did last year, Bruce Springsteen made an unannounced appearance Saturday at a Sea Bright, N.J., benefit concert to fight Parkinson's disease. On the eve of the third U.S. leg of his current world tour in support of "The Rising," which launched last night in Dallas, the Boss accompanied veteran Pittsburgh rocker Joe Grushecky onstage.

Joining Grushecky and his band the Houserockers midway through their set, Springsteen took the stage at the Tradewinds Nightclub to add guitar and harmony vocals to the Otis Redding classic "Can't Turn You Loose." Springsteen also supported versions of Grushecky originals "Homestead" and "Never Be Enough Time" before another New Jersey music veteran, Garland Jeffries, took the stage for a version of ? & The Mysterians' nugget "96 Tears" and his own anthem "Wild in the Streets."

Taking over lead vocal chores for "Fire" before resuming his sideman's role for Grushecky's "Pumping Iron," the Boss then sang John Lee Hooker's classic "Boom Boom" and his own "Light of Day," from which the benefit took its name. The set culminated with Chubby Checker's "The Twist," which brought '60s rock fixture Gary U.S. Bonds to the stage.

Bonds and his band the Road Rockers performed some of their signature numbers before Springsteen again took the stage for the Cajun standard "Jole Blon." Bonds wrapped his own set with his biggest hit, "Quarter to Three."

Organized by Grushecky's manager Bob Benjamin, who was diagnosed in 1996 with Parkinson's disease, the event raised over $30,000 for the Parkinson's Disease Foundation and Project ALS. The Light of Day concerts have yielded more than $100,000 in donations to date.