The resurrection of traditional Irish music owes a great deal to the Chieftains, who may be regarded as the Juiliard Quartet of the movement. But the expansion of the music to younger audiences rooted in contemporary rock sounds must be credited to a small number of Irish groups which took the tradition a step forward -- Planxty, the Bothy Band, Clannad, the Boys of the Lough and De Danaan.

If the Chieftains are the Irish Juilliard, then Planxty could be regarded as the Irish Beatles. In the early '70s, they created a new formula, mixing the Chieftains' pure traditional melodies with the emotional warmth of the ballad style that had become bastardized in the saloons of this century. Planxty explored and experimented along the lines of Pentangle, but maintained an acoustic stance and old-line flavor. Like the Chieftains, they served as researchers, arrangers and presenters of traditional music, but did the job much less rigidly. Planxty also benefited from the outstanding pipe-playing of Liam O'Flynn and the emotional warmth of its two eloquent singers, Andy Irvine and Christy Moore. Beneath it all were the beautiful textures provided by bouzoukis of Irvine and Donal Lunny, as well as mandolins, guitars, whistles and bodhran.

After four albums and several breakups, Planxty has reunited and "The Woman I Loved so Well" (Tara 3005) shows they are still the best of the lot. Although Planxty has always played its share of sprightly instrumental jigs and reels, it's their ballad style that sets them apart. They manage to make melancholy beauiful as they sing about Irish bandits and outlaws like "Johnny of Brady's Lea" and "Roger O'Hehir." They also take the American cowboy Billy Gray right out of Norman Blake's folk melody, "True Love Knows No Season," and bury him in the old sod by means of O'Flynn's mournful pipe solo.

Despite generally downbeat storylines, there's a buoyant spontaneity to Planxty's approach, with the bouzouki pulse interweaving subtle lines of counterpoint to so many songs. Typically, it's a long ballad, "Little Musgrave," that points up the group's strengths; it's a tearjerker, a timeless tale of a lovers' triangle moving toward inevitable tragedy. Moore signs the lead here, simply, unaffectedly, with a rich mournfulness. It's shattering and magical.

O'Flynn is the featured player on "The Brendan Voyage" (Tara 3006), a suite of orchestral pieces for uiellean pipes composed by Shaun Davey for a 48-piece orchestra conducted by Noel Kelehan. It's a different meeting point between old and contemporary forms of music and comes off surprisingly well. The pipes are used as a metaphor for the boat and crew that may have sailed from Ireland to America in the 6th century and the mixture of classical and folk flavors is quite enchanting, a bit reminiscent of the harp work of Alan Stivell.

After the first Planxty breakup, Donal Lunny joined up with some friends as the Bothy Band, a group that stayed together until 1979 and his return to Planxty. "The Best of the Bothy Band" (Green Linnet SIF 3001) is an exhilarating experience, propelled by Lunny's bouzouki, Peddy Keenan's wild pipes, Tommy People's impassioned fiddling and the gorgeous voice of Triona No Dhomhnaill. The Bothys sometimes strayed a little from the tradition, but always maintained the spirit. They sang in English or Gaelic, set down fiery dance rhythms and generally kept the spirits raised and/or flowing. "The Blackbird," a quintessential Bothy Band song, is included here. It starts off as a melancholy air, Keenan's pipes blowing away an ancient mist before settling down to a polite set dance with clavinet backing and ending with a rambunctious fiddle-paced reel.

Clannad, coming from the Gaelic-speaking area of Donegal, sings mostly in Gaelic, but anyone exposed to the archingly poignant soprano of Maire Ni Bhraonain won't care. This family group -- Ni Bhraonain is joined by her twin brothers and twin uncles -- sometimes sounds like a Renaissance choir and sometimes like 1970 Pentangle or Jethro Tull. Though Ni Bhraonain carries the leads, Clannad presents a rare family empathy that expresses itself in pure harmonies. They playing sometimes slides into a jazz-flavored bottom, but it's a move that seems as natural as hearing the songs in Gaelic. "The Makem and Clancy Collection" (Shanachie 52001) is more of a throwback to the jovial entertainment tradition these other groups rebelled against. Tommy Makem and Liam Clancy overemphasize the classic Irish spirit, something subtly absent from the other albums. One senses their "Irishness" in songs like "Willie McBride" and "Red Is the Rose," but most of the material is as safe as it is accessible and none of it is very old. Makem and Clancy are fun in a gruff, extroverted kind of way, but Planxty and the others are the virtuosos who elevate the traditions. Incidentally, almost all of the individual players in these great Irish bands have solo albums focusing on their instrumental prowess.They are also well worth searching out.