NO ONE IS more responsible for the resurgence of interest in the folk harp than the 40-year-old Breton virtuoso Alan Stivell. When his father built a Celtic harp from vague 16th-century designs, there had been neither an authentic instrument nor a player of note for almost four centuries.

No recording is more responsible for the harp vogue than Stivell's decade-old "Renaissance of the Celtic Harp," which until now had been available only as an import, on a catch-as-you-can basis, but that didn't stop it from becoming something of a cult item. To coincide with a rare Stivell tour (he'll be at the University of Maryland's Tawes Theatre tonight), Rounder has made the album available in a domestic pressing (Rounder 3067).

"Renaissance" is one of those magical albums: Stivell's Breton surname is Cochevelou, meaning "old springs," and the delicate ambiance of his work is decidedly ancient, mystic and marvelous. His evocative playing--a veritable cascade of notes--captures the three distinct styles of harp music that denote mastery of the instrument: "genintraidhe," which none can hear without bursting into laughter, "goltraidhe," which none can hear without bursting into tears, and "suantraidhe," which none can hear without falling into a delicious sleep. In moderns terms, that might qualify as "mood music," but the luxurious texture of Stivell's music is so delicious, its resonance so hauntingly familiar, that its cult status is easily understood.

Stivell has immersed himself in the Celtic tradition without succumbing to its purist limitations. "Ap Huw" and "Penllyn" are dolorous sonata-forms dating to the Middle Ages, while "Marv Pontkallec" is a classical setting for an elegiac Breton folk song. The quietly pulsating "YS," a suite dealing with the fifth-century capital of Cornwall and its spiritual destruction, presents an ethereal mix of harp, viola and Irish flute and seems as ancient as "Eliz Iza" with its modern mix of electric bass, drums, bagpipe and wordless chorus.

The second side of the album is a sprightly travelogue--there are jigs, airs, marches, waltzes and reels from Ireland, Scotland, Wales and Brittany, a swirl of sound that showcases Strivell's dexterity as much as side one showcases his interpretive skills. On subsequent albums, Stivell sang as well, but "Renaissance" is purely instrumental--and purely an aural treasure.

Californian Sylvia Woods was one of many folk musicians inspired to take up the harp by Stivell's trailblazing work. In 1980, she became the first American to win the harp prize in the prestigious All-Ireland competition (the harp is the national instrument of Ireland). Her debut album, "The Harp of Brandishwiere" (Tonmeister Records TNLP1213), is a concept suite for Celtic harp inspired by tales of a legendary harper and his spiritual battles to save the innocent Isle of Spring from the evil sorcerer Gourenspur. It also has a standard boy harper meets girl harper, loses-and-wins-her-back-again subtext.

It's a Celtic folk variation on the creation myth and, like Stivell's album, wholly instrumental and wholly original in composition, with Woods establishing some lovely conjunctive sounds (particularly with Christopher Caswell's wooden flute). Woods plays three harps--a 24-string minstrel harp, a 36-string Gwydion harp and a 32-string Celtic harp, the last one nylon-strung. Different harps produce different textures, ranging from the hammered dulcimer vitality of the steel-strung versions to the delicate classical-harp tones of the nylon-strung instruments.

The best parts of Woods' album are the simplest--the haunting and theme-establishing "Legend," the singing tones and virile nature of "Dialogue With a Brook," the breathy calm of "Lament" and "Morning Calm." "Gypsy Mirage" and "Gourenspur" are evocative tone poems that would have fit into "The Dark Crystal." Woods seems less concerned with ethnic purity than with emotional impact, and though the finale is a bit klutzy, her suite is delightfully accessible.

The same can be said for Magical Strings' "Spring Tide" (Flying Fish FF-282). Magical Strings is the splendid harp and hammered dulcimer duo of Philip and Pam Boulding. Their music--occasionally augmented by flute, bouzouki and field organ--is warm and graceful. Much of it is sonically gorgeous as well, particularly a trio of hymn-like Welsh harp tunes that dissolve into turn-of-the-century parlor gaiety, and the enchanting "Aurora's Lullaby," which segues into a plaintive Turlough O'Carolan melody, "Carolan's Welcome."

The Bouldings share not only a marriage but a pure musical empathy. Their instruments--one plucked, the other struck--weave in and out of each other like avid Maypole dancers.

The Bard Carolan, a blind, 16th-century harper, was a legendary wandering minstrel who wrote thousands of ingenious songs for patrons and friends; the lyrics have virtually disappeared, but the melodies linger on and still form the basis of much traditional Irish music.

Like the Boulders and most harpers, Melissa Morgan draws extensively from the Carolan well, particularly on "Erin's Harp" (Kicking Mule KM315).

Unfortunately, Morgan's playing shows technical facility but little emotional flair. Too much of the album sounds like Introductory Harp, a predictable sampler of short tunes presented with little embellishment or imagination. Only the stately folk-chamber sound of the "John Irwin" duo with guitarist Jonathan Parker and the glass-harp like harmonics of "O'Carolan's Air" suggest much character.