There is something very cool about seeing artists get excited over the chance to catch other musicians perform, and it's a whole new level when they take the stage with them for an impromptu song or set.

Both happened at Pipeline Café recently, first when Jackson Browne unexpectedly joined Ozomatli on stage for a few of their songs, then again last week when Matisyahu got to town a day early and asked Bamp Project promoters to take him to Mayer Hawthorne's show.

Browne's appearance with Ozo was set up by mutual friend Mark Cunningham.Already on O'ahu and friends with the band and promoter Tom Moffatt, Browne stopped in at Pipeline Café to chat up the band before their show and ended up joining them on stage for "Saturday Night" and played through "Como Ves."

Call it good timing for Browne to vacation here, and even better timing for the fans at the Ozomatli show.

As for Matisyahu and Hawthorne, Aubry Boutin, one of the Bamp Project co-owners, said the Hasidic Jewish reggae rapper was stoked to learn Hawthorne was playing the night he arrived and asked the promoters to take him to the show from the airport (Bamp put on both concerts).

Turns out, Hawthorne is a fan of Matisyahu, so if ever there is a collaboration between the two, you could say it started here.

While Matisyahu's concert sold out, Hawthorne's show was about half full. Bamp Project promoters said they expected the lighter turnout because he's not yet as well known.

But he will be. Hawthorne on stage is a cross between Buddy Holly and Elvis Costello in looks, but with a Motown feel. Dressed in a red suit and Nikes and sporting bookworm glasses,Hawthorne also played covers like Biz Markie's "Just a Friend" and joked with the crowd about having mahi mahi for the first time. He closed with "Mahalolujah."

It's a safe bet he'll perform in the Islands again, but don't expect $25 tickets the second time around. Justin Timberlake and John Mayer are among the musicians Twittering to check him out as a rising star.

Last Saturday's tsunami threat forced the cancellation of several events and wreaked havoc on those that kept going. The Hawaii Ocean Expo 2010 at Blaisdell Exhibition Hall felt the brunt of the threat.

"The first half of the show was like a ghost town, but after the all-clear it got busy,"said Russ Inouye, one of the expo's creators. "We were packed all day on Sunday, but on Saturday we were thinking 'a tsunami ruins an ocean expo?' Are you kidding?"

Also, C4 Waterman has rescheduled its free demo day for stand-up paddleboarding for 9 a.m. tomorrow at Sand Island Park.