Although Houston, Texas, may seem an unlikely base of operations for a Celtic band, it is, in fact, the home of Clandestine, a band that''s highly regarded both in the United States and abroad.

At the heart of the group is E. J. Jones, the band''s bagpiper/whistle-player, who first came up with the band''s name when he was in high school. He had been playing the formal, marching-band style of bagpipe music since he was 11, but the instrument really came alive after he heard the loose, rowdy piping style of the Tannahill Weavers. "They were my Rolling Stones," Jones told Dirty Linen magazine last summer.

In college, Jones met guitarist/vocalist Jennifer Hamel, who remains as the only other original member of the band. With Gregory McQueen on electric fiddle, and Emily Dugas (the newest member) on vocals and percussion, the quartet delivers a loose, lively blend of traditional, contemporary and original Celtic music.

They''re not as pugnacious as Sally''s Gap (which you''d expect to find in an Irish biker bar), as darkly mystical as Tempest (which you''d expect to find bewitching the habitués in a nightclub of the damned) or as brazen as The Wicked Tinkers (which you''d expect to see at the forefront of a furious charge by Scottish berserkers). Still, Clandestine exudes a rollicking energy--like something you might expect to find in a Celtic college pub.

If Jones'' bagpipes are the soul of the band''s music, the beautifully harmonized vocals by Hamel and Dugas are it''s heart. Richly sensual, the singers'' voices twine around each other to create a whole that''s greater than the sum of its parts while, at the same time, pushing each other just enough to keep the music from seeming too predictable. And cutting through it all, from the pipe''s wild drone to the civilizing vocals, there''s McQeen''s violin whipping the music to new frenetic levels, while keeping it together at the same time.

This marks the band''s third appearance at the London Bridge Pub. Word of mouth from their first appearance was so great that the last time they were there, the Pub was so packed there was hardly room to breathe. This time around, the band has a two-night stand. Even so, anyone who wants a place to sit would be well advised to get to the Pub early. Clandestine plays the London Bridge Pub, Wharf #2, Monterey, Thursday and Friday, 9pm 655-2879.