Singer-songwriter Vicky Pratt Keating led a trio at the Birchmere Wednesday night, though it didn't always sound like one. That's primarily because she was accompanied by Greg Howard, who plays the Chapman Stick, an odd-shaped string instrument that combines characteristic features of the guitar, bass and keyboard. During some of the more animated tunes, when Howard and drummer Parker Daggett were given free rein, the arrangements occasionally recalled the music Joni Mitchell made with jazz fusion ensembles in the '70s.

These tunes often found Keating using her lovely soprano voice to convey wordless chants and conjure exotic moods. In more intimate settings, while playing alone or collaborating with her band mates, the songs she performed from her current album, Blue Apples, as well as more recent tunes, often demonstrated her flair for writing refreshingly varied material -- by turns tender, passionate and whimsical.

Keating also allowed Howard ample time to display not only his remarkable facility for playing the Stick but also his gifts as a composer and colorist. An original piece called "Goya's Dream," an imaginatively arranged flamenco-tinged ballad, was particularly alluring.