On a sunny Saturday in Onset, the vibes were immaculate – the sounds of vibraphone, saxophone, guitar and more carried through the air around West Central Avenue as jazz band Bob’s Chili Combo played their third One-Porch Onset Porchfest on Sept. 14.

Classic tunes mingled with original compositions by vibraphone player Bob Keough as the seven-person group played their set on the back porch of Onset resident and guitarist Mitch Rosenberg.

The porch is a “great venue [with a] nice stage,” said Keough. “It’s easy to deal with.”

The group formed over time, said Keough. First, a 2019 jazz retreat hosted by Rosenberg brought many players together, and several others joined since.

“Suddenly, you’ve got a band,” said Keough.

The group now consists of Keough, Rosenberg, alto saxophonist Jack Davison, tenor saxophonist Ritse Adefolalu, trumpet player Peter Orne, bassist Mark Pfaff and drummer Mike Chamness.

The annual performance takes place in either August or September and is “just fun for the neighborhood,” Keough said.

“We got a big band so our own entourage gives us a base of an audience,” he said, adding that there are “some new faces in the crowd” this year.

In the past the band played “whatever sounded good,” said Keough. But over the past several months, the band decided to “get a little more serious [and] a little more ambitious with some of the tunes we were playing and really work on them.”

This year’s set included Adefolalu’s arrangement of the 1949 Boston favorite “Charlie and the MTA,” originally by The Kingston Trio. The song also featured Adefolalu on vocals.

For audience member and Brookline resident Chris Johnson, Saturday’s concert was like a piece of Boston in Wareham. 

“The cool thing is that Brookline has its own porch fest,” he said. “This is reminiscent of what we see in Brookline ... it’s a great thing for the community.”

According to Keough, the group rehearses every two or three months – either in Onset or Hamilton – and every rehearsal, either Keough or Chamness makes the chili.

Not only is Bob Keough’s chili the band’s namesake, it “holds the group together,” he joked.

And according to Orne, the chili gets better every time.