As the saying goes, reports of the Beach Boys' death have been greatly exaggerated. Despite attempts to dismiss them as passe, the group's fabled harmonies have seldom sounded richer on stage. Last night's show at the Capitol Centre was a sharp contrast to sloppy, halfhearted local concerts of recent years. The vocals were strong and the arrangement executed precisely.

The evening's high point came on the second song, "Sloop John B." Brian Wilson - the band's reclusive, troubled creative leader - was making a rare stage appearance. He took the lead vocal in a strong, resonant voice that redeemed his recent hoarse, off-key performances. It was another small but encouraging comeback by rock 'n' roll's greatest musical innovator. The group's four-part harmonies have often sounded tired and thin on recent tours. But last night the voices blended in peak form.

On songs like the old "In My Room" and the new "Good Timin'," three background voices would slide underneath and above the lead singer to create four different vocal themes. In a special threat, Christine McVie of Fleetwood Mac came on stage to sing harmony on the encores of 'Good Vibrations," "Barbara Ann" and 'Fun, Fun, Fun."

The Beach Boys aren't all the way back yet. They still rely too heavily on their '60s repertoire. Only Brian Wilson's new arrangement of "Short'nin' Breed" broke new musical ground. And the older Wilson stayed in the shadows too much. But with the group's former leader reinvolved in the harmonies back in form, there is once again reason for optimism about the Beach Boys.