You better believe it

From singing R&B on the stoops of Brooklyn to Grateful Dead covers in the recording studio, the Persuasions have been spreading their a cappella sound for almost half a century. For the record, we're partial to their rendition of the Dead's "Ripple," a gorgeous gospel go of it with a deep, lush bass. The quintet has recorded for or performed with Bette Midler, Stevie Wonder, Van Morrison, Paul Simon, and B.B. King, and tonight they'll entertain for you. The group unleashes its rich, heavenly harmonies with three of the original members at the Regattabar. 7:30 and 10 p.m. $25 (7:30 p.m.), $22 (10 p.m.). Regattabar, Charles Hotel, 1 Bennett St., Harvard Square, Cambridge. 617-395-7757. regattabarjazz.com