Ever since Van Morrison's "Astral Weeks" appeared in 1968, bands from Ireland and Great Britain have tried to capture the elusive musical beast of Morrison's invention known as "Celtic Soul."

Ireland's Energy Orchard is the latest purveyor of this hybrid to reach these shores, and the band's set at the 9:30 club Saturday night showed it has the basics down. Two- and three-chord progressions with simple melodies and lots of harmonies were combined with blues harmonica and guitar leads reminiscent of J.J. Cale and, voila, a Celtic soul stew.

The band was at its best when two acoustic guitars were used to set the mood, and less convincing on its Z.Z. Idol rockers, "This House Must Fall" and "Baby, Please Don't Go." The lush waltz "King of Love" was followed by the jig "Somebody's Brother."

Bap Kennedy sang his overly earnest lyrics with a sense of humor and conviction -- a nice combination -- while the rest of the band played simply, letting the songs be the focus. Kevin Breslin's keyboard playing was the exception, pushing simple folk songs into the land of anthem.

Kristen Hersh of the Throwing Muses opened the show with an intriguing solo acoustic set, taking her buttery voice through its paces, the roller-coaster melodies and surreal lyrics out for a spin.