It was a night for memories and lovers at Constitution Hall Saturday, when a trio of venerable vocal harmony groups sang music as it used to be -- evoking the days, to paraphrase one singer, when you could hear the words, the music was slow and dancing was a slow grind.

Opening were Ray, Goodman and Brown, performing a lengthy set that included feathery ballads such as "Inside of You." Their harmonies were impeccable indeed, but stale choreographed steps and hackneyed melodramatics soon became tiresome.

Next up were the Manhattans, a vocal quartet that's been singing for more than 20 years. With a bit more energy than the previous trio, they sang a stunning version of Sam Cooke's "You Send Me" and rocked the house with the rousing gospel of "Everybody Sing a Song."

Celebrating their 35th anniversary and headlining the show were the Dells, arriving on stage to a standing ovation. With the exception of "Sittin' on the Dock of the Bay," which sounded more like aerobics workout music, their classic oldies, such as "Stay in My Corner" and "The Love We Had (Stays on My Mind)," were sung to lush arrangements designed apparently for all those lovers in the house. The Broadway punch of "My Baby Just Cares for Me" was augmented by a 10-piece horn section, but the set's highlight, oddly enough, was a moving rendition of "Wichita Lineman."

These acts rely on rich traditions of bygone accomplishments to carry the show, but here and there their suave shtick seemed mighty timeworn. And it was a pity that all three groups, which rely so heavily on the clarity of vocal harmonies, were hampered by an intermittent buzz in the sound system.