Bob Dylan and Neil Young could tell even Frank Sinatra a thing or two about how it feels to be flying high in April only to be shot down in May. After all, both have seen their recordings praised and damned with equal vigor by the rock press over the years. Dylan's work alone has seen so many ups and downs in the view of critics that, last spring, following the rosy reviews that greeted "Oh Mercy," Spy magazine cited no fewer than 16 times in 22 years that one scribe or another has heralded Dylan's comeback. And every comeback, of course, was preceded by a ream of reviews bemoaning Dylan's creative drought.

Every so often, though, Dylan releases an album such as "Planet Waves" or "Empire Burlesque" that doesn't inspire much comment one way or the other, an album that doesn't mark a precipitous fall from grace yet leaves plenty of room for improvement. Or, perhaps a few similarly lackluster albums down the road, for another comeback.

The new "Under the Red Sky" (Columbia) is that kind of album -- uneven, a bit slapdash but nonetheless far more enjoyable than Dylan's last indisputable dud, "Knocked Out Loaded." It departs sharply from the atmospheric soundscapes that characterized Daniel Lanois's production on "Oh Mercy," making it Dylan's most distinctive and acclaimed release since "Blood on the Tracks" in 1975. This time around it's Don Was and David Weiss of Was (Not Was) who are at the controls, and instead of trying to imitate Lanois's affection for the rural Deep South and "Oh Mercy's" languid blend of dobros, guitars, accordions and saxophones, they set out to conjure the electric, defiant Dylan of old by bringing a lot of familiar faces into the studio and letting the sparks fly.

What sparks there are, though, are few and far between. Part of the problem, it seems, is that Dylan arrived at the studio almost empty-handed. If several tunes on the album weren't composed on the spot, they could just as well have been, and despite the presence of George Harrison, David Lindley, Al Kooper, Bruce Hornsby, Elton John, the late Stevie Ray Vaughan and his brother Jimmy, the cast can't compensate for the absence of worthy songs. On the contrary, for all the talent assembled, the arrangements often fall curiously flat, and are notable mostly for drummer Kenny Aronoff's trademark wallop and the way Kooper's sweeping R&B-tinged organ occasionally evokes mid-'60s Dylan.

The album opens with "Wiggle Wiggle," the slightest of several blues romps and the first indication that Dylan didn't take this recording nearly as seriously as "Oh Mercy." The throwaway lyric -- "Wiggle to the front/ wiggle to the rear/ wiggle till you wiggle right out of here" -- may outscore everything else on the album's doggerel scale, but similarly mundane, off-the-cuff rhymes also undercut both "2 by 2" and "10,000 Men."

Of the tunes that sound as if they hatched out of studio jam sessions, only "TV Song" manages to leave a strong impression. Here Dylan, assuming the role of a soapbox fanatic, his voice snarling over Hornsby's boogie-laced piano, rails against the scourge of television: "It will lead you into some strange pursuits/ lead you to the land of forbidden fruits/ scramble up your head and drag your brain about/ sometimes you have to do like Elvis did and shoot the damn thing out."

That rant, along with "Unbelievable," a similarly caustic diatribe decrying the utter madness of modern life, and the opening bars of "Handy Dandy," which suggest Kooper is about to rework "Like a Rolling Stone," is about as close as Was and Weiss get to capturing Dylan's glory days -- not very close at all. The album's remaining highlights -- the haunting love song "Born in Time," the simple but enigmatic fable "Under the Red Sky" and the contemporary spiritual "God Knows" -- are more in tune with the contemplative side of "Oh Mercy" but sorely lack Lanois's seductive touch.

Neil Young and Crazy Horse: 'Ragged Glory' Like "Oh Mercy," Neil Young's last album, "Freedom," was widely and justly hailed as one of his strongest releases in years, a welcome change from his recent and erratic flirtations with synth-pop, country, rockabilly and blues. But now that Young is reunited with Crazy Horse on "Ragged Glory" (Reprise), even "Freedom" seems a bit tame and inconsistent by comparison. With its squalling guitars, jackhammer rhythms and mixture of hippie sentiments, eco-anthems and emotionally raw moments of self-appraisal, "Ragged Glory" ranks right up there with Young and Crazy Horse's 1979 classic "Rust Never Sleeps."

It's also as raucous an album as Young and Crazy Horse have ever recorded. (For the record, Young is joined by bassist Billy Talbot, drummer Ralph Molina and guitarist and former Horseman Frank Sampredo.) Even the dewy-eyed '60s odes "Country Home" and "Days That Used to Be" have a garage band intensity, a one-two punch powered by overdriven guitars and a pummeling beat. The same combination keeps the nostalgia from suffocating "Mansion on the Hill" ("psychedelic music fills the air/ peace and love live there still") and sustains the album's 10-minute romantic flights, "Love to Burn" and "Love and Only Love."

The closest thing on "Ragged Glory" to a ballad is a choral-cum-Hendrix arrangement of "Mother Earth (Natural Anthem)." Recorded at last winter's Farm Aid benefit in Indianapolis, the song is bound to become a concert favorite, but it could well be eclipsed by another tune on the album with a title that's unfit to print in a family newspaper. Suffice it to say, it's easy to imagine a lot of fans wallowing in remorse while trying to match Young's wailing tenor decibel for decibel on the chorus, "Why do I keep {expletive} up?"

Crazy Horse: 'Left for Dead' Before Young could reunite with Crazy Horse, he had to patch up some serious differences between himself and the band members. The last Neil Young-Crazy Horse split preceded Young's excursion into his jazzier "Blue Note" period a few years ago, and to judge by the new Crazy Horse album, "Left for Dead" (Sisapa), the separation was something less than amicable.

That much is clear right from the start. The powerfully candid opening track, composed shortly after the breakup, vents the band's anger about being "left for dead": "You've been running with the mean and the bold/ Long time comin' now you're gettin' old/ so they burn you, leave you dyin' in the sun/ You always knew that one day they'd find a faster gun."

Still, the bad blood wasn't so thick that it prevented the band's current lineup -- Talbot, Molina, lead guitarist Matt Piucci and vocalist Sonny Mone -- from paying tribute to Young. Two of the albums best songs, in fact -- "World of Love" and "Show a Little Faith" -- sound as if they were torn right out of Young's songbook, with Mone's whining, drifting voice making the comparison all the stronger. The album's real strength, though, lies in the primal thrust of the band's guitar and drums, which is only briefly compromised by a couple of tepid rock ballads and some metalish, over-the-top singing by Mone.