It's 6 p.m. on Sunday, but at the Pier View Restaurant in Onset, it feels like Saturday night. The room is too crowded for dancing (try as people might), the bartender is calling for backup, and the wails of a jazz saxophone escape into the street.

"We've got people calling up all day asking if we've got jazz," said Steve Baptiste Jr. the manager of the lounge portion of the restaurant that his father started 30 years ago. "People seem to be liking it."

But this isn't your typical jazz performance. First of all, it takes place on Sunday nights from 5 to 9 p.m. And there is no program or any announcement as to who's performing or what they're playing - this past Sunday, the bassist walked in an hour into the set. A percussionist joined about an hour later. And despite recruiting the top musicians in Boston and Providence, the musicians perform for free just because they love to play.

"This is not a money day, this is a family day," said Desso Bryant, a caterer by trade but jazz percussionist by heart who started the performances in November by recruiting his friends and collaborators in the music industry. "I'm just trying to make some music down here. Lot's of musicians have no platform or opportunity to play, this is the place to cut your teeth."

Onset has a long history of jazz, but the clubs and other music venues have slowly closed since their heydey in the 1940s and 1950s when such performers as Duke Ellington, Ella Fitzgerald and others routinely visited. Bryant is trying to recreate that atmosphere.

"It's a throw-back to the Fifties," said John Tavares, a native of West Wareham whose younger brothers performed as Tavares and had a string of R&B hits in the 1970s. "We used to go from club to club, it was great, they're starting to do that again, I think."

Most importantly, the music is good. Really good.

"It's become a gathering place - the word's out," said Liz Sullivan, who dabbles in jazz vocals herself and grew up in the jazz scene in Onset. "It's all word of mouth, all musicians telling musicians... it's attracting musicians, that's how you know it's good."

Most of the performers are affiliated with Berklee School of Music or New England Conservatory, and they have played with yesterday and today's best jazz performers including Wynton Marsalis, The Platters, The Drifters, Max Roach and Allan Dawson. Bryant schedules a core group to perform each week, but other players are welcome to join, and the lineup is flexible.

Mibbit Threats just returned to Providence from touring in Japan and received a call at 5:05 p.m. when Bryant realized they had no bassist for the evening.

"It's all the big boys in town, guys I've played with," said Bryant. "Around Berklee there are all these spots that performers go by when you come to town, it's low pay, but you have to go." He said that this is what he wants to create in Onset.

The crowd is certainly appreciative. In addition to the musicians who stop in (and not just to play, according to Sullivan, several have come by just to listen), a diverse crowd of local regulars, college students from Boston, and beachgoers lured by the music, pack the bar.

"I was devastated when the [Onset Bay] Blues Cafe closed," said Wareham resident Liza Blakemore. "I'm so glad that Stevie's picked it up. You need music in a community."

Bryant says the best is yet to come.

Now it's spring, the weather's nice, the beach is starting up...I've got musicians calling me to get in here."