IT HAS BEEN seven years since their self-titled debut album firmly established the Baltimore-Washington band Celtic Thunder as one of the best Irish folk acts in America.

After many personnel turnovers and frustrating delays, Celtic Thunder has finally released its second album, but "The Light of Other Days" builds on the strengths of that first album as if one had followed the other by a year.

Celtic Thunder is still characterized by a rare balance between vocal songs and instrumental tunes, by an Irish-American rather than Irish perspective on the music, and by some of the best original material in the field. Founding member Terry Winch, an award-winning poet, has used his low-key naturalism to evoke scenes of modern Belfast and turn-of-the-century New York in three songs. He sings the militant anti-British anthem himself but turns over the more affectionate immigrant songs to the lovely soprano of Laura Murphy.

Murphy's luxurious vocal on the ancient, sad "Oft in the Stilly Night" recalls De Danann's Mary Black. Dominick Murray sings two of his own songs -- the comic novelty number, "The Bachelor's Warning," and the exquisite love ballad, "The Maid of Black Curls" -- in his warm, resonant tenor. Of the 11 instrumental tunes grouped in four medleys, five are original compositions that could easily find a place in a new edition of O'Neill's book of tunes.

The way fiddler Rob Thornburgh slips little grace notes around his strong melodic lines, it often seems as if he's playing a duet with himself. Jesse Winch's work on the bodhran, the Irish hand drum, gives Celtic Thunder a rhythmic authority that most acoustic folk bands lack. During the band's signature tune, "The Thunder Reel," the bodhran engages in an accelerating percussion duet with the rattling toes and heels of the band's champion stepdancer Regan Wick.

CELTIC THUNDER --

"The Light of Other Days" (Green Linnet SIF 1086). Appearing Sunday at Kelly's Irish Times.