If you've never seen the Neville Brothers headline a live show, you may not understand why so many music insiders consider them one of the very best acts in Anglo-American music. They've never quite captured their transcendence on tape, so their albums won't convince you, and it takes the Nevilles about half an hour to warm up, so seeing them as an opening act won't do the trick either.

The Neville Brothers Band opens the show for Linda Ronstadt at Merriweather Post Pavilion tomorrow, but you really have to see the Louisiana sextet over the course of a full show to appreciate the effect of America's finest rhythm section, the English language's best ballad singer and the group's heady mix of New Orleans second line, soul harmony singing, rock guitar, jazz sax and reggae congas. There's no other concert experience quite like it.

On last year's "Yellow Moon" album, the Neville Brothers came closer to capturing their magic in the studio than they ever had before. Producer Daniel Lanois created a stripped-down, liquid sound with each song focusing on one of the band's individual strengths. Lanois's engineer, Malcolm Burns, and the band co-produced 11 of the 13 cuts on the new Neville Brothers album, "Brother's Keeper" (A&M), and they tried to re-create the heavily echoed, ghostly sound of "Yellow Moon." To a large extent, they succeeded, but the songwriting on "Brother's Keeper" simply isn't as strong as on its predecessor.

Instead of outside material by Bob Dylan, Sam Cooke and the Carter Family, the new album takes its outside material from Leonard Cohen, Junior Parker and Nashville songwriter Gary Nicholson. Instead of original material firmly rooted in the specifics of Rosa Parks, New Orleans voodoo and Mardi Gras Indians, the new originals brandish bland homilies and extended vamps rather than fully developed songs. The Nevilles are such good players and singers that the results are thoroughly enjoyable, but anyone who has felt the thrill of the band's live show expects more than just "enjoyable" from the Neville Brothers.

There are some indisputable highlights. The Eurythmics' Dave Stewart produced the Nevilles' version of Cohen's "Bird on a Wire" for the movie of the same name, and he turned it into a superb showcase for Aaron Neville's ballad singing. Aaron converts Cohen's overly precious lyrics into a confession of the desperate, paradoxical need to be both independent and loved. You can hear both the fear of commitment and the need for connection in Aaron's translucent, fragile high tenor.

Aaron's only other ballad spotlight comes on "Fearless" (with backing vocals by Ronstadt, his top-10 duet partner); he transforms Nicholson's platitudes about optimism by revealing in the weariness of his voice just how hard-won that optimism can be. He gets one verse in each of the album's bouncy hymns ("Brother Jake," "Steer Me Right" and the title tune), and he makes the most of his chances, but we'll have to wait for his forthcoming solo album (currently being produced by Ronstadt) to get a full dose of Aaron's vocals.

Several other songs recall the classic Southern soul of the '60s: Art Neville does a good Brook Benton imitation on "Fallin' Rain," and Cyril Neville does a good Otis Redding imitation on "Witness." On the other hand, many of the album's songs are interchangeable reggae/soul hymns to universal brotherhood with music as bland and vague as their homilies; it's nearly impossible to distinguish "Jah Love" (written by Cyril with U2's Bono) from the three sound-alike songs with "Brother" in the title. Worst of all is Art's spoken recitation on "Sons and Daughters"; he sounds much more solemn and weighty than his empty cliches would seem to merit.

The bottom line is this: It's always a treat to hear Aaron and Art sing and to hear Willie Green and Cyril play drums. But in three years, how many of these songs are still going to be in the Nevilles' live set? None of them, probably.

'The Classic Aaron Neville: My Greatest Gift'

In addition to his work with his brothers, Aaron Neville has enjoyed a long and fruitful solo career. He recorded a series of singles with producer Allen Toussaint for Minit Records in 1960-63; he recorded an album of material with producer George Davis for Parlo Records in 1966, including his No. 2 pop smash, "Tell It Like It Is"; he returned to Toussaint to make singles for various labels between 1968 and '77. Since the Neville Brothers formed in 1978, Neville has done occasional solo gigs and made guest appearances on other albums (Hal Willner's "Stay Awake," Rob Wasserman's "Duets" and Linda Ronstadt's "Cry Like a Rainstorm -- Howl Like the Wind").

Most of Aaron's early singles have been re-released in Europe but not in his homeland. That travesty has now been mitigated by the release of "The Classic Aaron Neville: My Greatest Gift" (Rounder Records, 1 Camp St., Cambridge, Mass. 02140), an anthology of 12 songs from 1968-77. Toussaint wrote five of the songs and produced all 12, including a stark remake of "Tell It Like It Is." As they sought the right formula for commercial success, Neville and Toussaint worked out a fertile blend of New Orleans R&B and the progressive soul of Curtis Mayfield, Marvin Gaye and Stevie Wonder that was so popular in those years.

They never struck chart success, but they made some fascinating music, marrying Neville's fragile voice to the tough, funky music of the period. The anthology includes Neville's original version of "Mojo Hannah" (a staple of the Nevilles' live shows) plus his spectacular versions of "Where Is My Baby" and "Hercules." This is a must-have album for any true connoisseur of soul singing.

The Meters: Two Reissues During the mid-'60s, the top live band in New Orleans was the Neville Sounds, an octet featuring the four Neville brothers and four other musicians. They were playing at the Ivanhoe Club in the French Quarter when the club's budget forced them to cut back to four pieces: keyboardist Art Neville, guitarist Leo Nocentelli, bassist George Porter Jr. and drummer Joseph "Zigaboo" Modeliste. Before long, this quartet became the house rhythm section at Allen Toussaint's studio and started recording on their own as the Meters. In 1969, they had Top 40 instrumental hits with "Sophisticated Cissy" and "Cissy Strut."

They became known as "New Orleans's Booker T & the MGs," adding a second-line syncopation to the lean, impeccable funk served up by their Memphis colleagues. The Meters recorded with everyone from Lee Dorsey and Dr. John to LaBelle and the Wild Tchoupitoulas, and Little Feat cites the Meters as the model for their own brand of funk. The out-of-print Meters albums have become high-price items in collector shops, but now Rounder Records has released two valuable anthologies of Meters music.

"Look-Ka Py Py" contains early instrumental material (but non-hits) that highlights the quartet's savage brand of syncopation -- sharp enough to snap a dancer's neck. Porter may well be America's best electric bassist, and he's often the lead instrument on these original tunes, melodically moving even as he radically staggers the beat. "Good Old Funky Music" collects vocal numbers from later in the band's career when Cyril Neville had joined as a percussionist/vocalist. Mixing originals with standards such as "Rockin' Pneumonia," "Jambalaya" and "The Riddle Song," this album is more accessible but less distinctive.

George Porter and C.P. Love George Porter may be the world's best funk bassist, but he's far from the world's best singer or songwriter. His debut solo album, "Runnin' Partner" (Rounder), suffers from his attempts to fill all these roles. Still, half of the 10 cuts are notable triumphs. Earl King, New Orleans's master songwriter, not only contributed two tunes with witty, streetwise lyrics matched to catchy, syncopated melodies, but he also played hot guitar on them. Porter himself composed three instrumentals that recall the classic Meters workouts on "Look-Ka Py Py." You won't hear more muscular, more inventive bass lines anywhere.

Porter and Metermate Leo Nocentelli both play on the new six-song EP, "C.P. Love" (Orleans Records, 828 Royal St., New Orleans, La. 70116). Love is a fine soul singer in the old Memphis style, and the addition of New Orleans funk underneath gives his classicism a welcome freshness. Love does a good job with the Young Rascals' "A Beautiful Morning" and Otis Redding's "My Lover's Prayer," but Love's own originals, "Stubborn Girl" and "True Blue," are the real surprises -- solid soul compositions delivered with a light, personal touch. This is an unexpected gem for any lover of Southern soul singing.