It's nothing new for record companies to scavenge the archives of dead legends for unreleased material; if you doubt it, just take a look at the number of posthumous releases by Jimi Hendrix. (I count more than 250 from a man who only issued four albums during his lifetime.) Now we're seeing the same phenomenon playing out with more underground musicians, and the results are mixed, judging from the trio of new discs by late cult-hero singers and songwriters Elliott Smith, Nick Drake and Jeff Buckley.

For a posthumous release to be worth anything more than a historical footnote, you have to ask: Is this music the artist would have released had he lived? Held up to that standard, as well as the beginning-to-end pleasures contained in its 24 tracks, Smith's sprawling double album "New Moon" is by far the pick of the latest crop.

Smith first made his mark on the music world in the early '90s as part of the Portland-based indie-rock band Heat Miser. Striking out on his own in 1994, he released five albums of gorgeous, introspective Beatlesesque pop; made his biggest impact on the mainstream when he performed "Miss Misery" at the 1998 Academy Awards (nominated for its place on the soundtrack of "Good Will Hunting," it lost out to that dreadful tune from "Titanic"), and died under mysterious circumstances at age 34 in 2003 from what may or may not have been self-inflicted knife wounds to the chest.

A lo-fi devotee, Smith recorded constantly, and he released most of what he put down on tape. But the tracks on "New Moon" stem from the transitional period between Heat Miser and the full blossoming of his solo career, from 1994 to 1997, and it seems likely that they simply fell between the cracks. Now, his friend Larry Crane, owner of Portland's Jackpot! Recording Studio, has compiled these tunes at the request of Smith's family, showing the devotion of a fan by tinkering very little with the bare-bones productions and the ears of an objective archivist by choosing the strongest songs and the ones that best illuminate Smith's talents.

To that end, we get a poignant reading of Big Star's "Thirteen," a song with a melancholy yet upbeat vibe that obviously set the tone for many of Smith's originals at the time; a work-in-progress version of "Miss Misery" that illustrates how the musician used the process of recording to hone his material, and previously unheard gems such as the wily pop tune "Looking Over My Shoulder," the wistful "Angel in the Snow," and the obligatory Beatles nod "New Monkey" -- all of them good enough to stand beside the best material Smith released in his day.

Unjustly slighted by some listeners for his alleged mopiness, Smith's prevailing mood on "New Moon" is actually one of guarded optimism -- and the same can be said of Drake on "Family Tree." Barely 20 at the start of his career, the English musician released three brilliant albums between 1969 and 1972: the lush orchestral-pop masterpieces "Five Leaves Left" and "Bryter Later" and the Spartan acoustic effort "Pink Moon," recorded not long before his death, a likely suicide, from an overdose of antidepressants in 1974.

Drake's career has benefited from a surge of interest in recent years, and he's emerged as a major influence on ork-pop bands such as the Decemberists and the Arcade Fire and even won a hint of the pop stardom so elusive in his lifetime. The sound of the 28 tracks on "Family Tree" will be familiar to anyone who's heard the title track of "Pink Moon" in that now-infamous car commercial, since these are mostly spare acoustic demos recorded at home on a home reel-to-reel tape machine long before the making of "Five Leaves Left." In that sense, the new disc could have been an ideal companion to "Pink Moon" -- an optimistic bookend to the lonely pessimism of Drake's last release. But the material simply isn't as strong.

The artist's family clearly was scraping the bottom of the barrel here, including two songs written and performed by Drake's mother Molly; other tunes that find him harmonizing with his sister Gabrielle and playing clarinet with his aunt and uncle on a piece by Mozart, and his first tentative and largely unsuccessful stabs at songwriting, via tracks such as "They're Leaving Me Behind," "Blossom" and "Come Into the Garden." But the best moments by far are the handful of revealing covers that show him polishing his husky baritone and unique finger-picking guitar style, including "Strolling Down the Highway" by British folk hero Bert Jansch, the traditional "Black Mountain Blues" and "Cocaine Blues," which was popularized by Blind Boy Fuller.

Trimmed down to an EP or tacked on as the bonus tracks in a box set, these songs would have been worthy additions to Drake's discography. As it is, though, "Family Tree" is mostly filler and eminently skippable -- yet as exploitation goes, it's still preferable to "So Real: Songs from Jeff Buckley."

The hyper-emotional musical offspring of '60s folkie Tim Buckley, Jeff won a passionate cult following for his live performances, but his recorded legacy doesn't support his lofty reputation: During his lifetime, he only released one mediocre EP and one promising though overrated album. (Fans of 1994's "Grace" wax rhapsodic about Buckley's reading of "Hallelujah," but one suspects it's because they never heard the superior original by Leonard Cohen or the cover by John Cale.)

Buckley drowned in the Mississippi River at age 30 a decade ago last Tuesday, but that hasn't stopped his survivors from releasing everything he left behind. Partly a collection of alternate takes and partly an unwarranted greatest-hits set, "So Real" includes eight of the 10 tracks that appeared on "Grace." Others are familiar from "Live at Sin-e," and the few that appear in different versions aren't any better or more noteworthy here. In fact, the only real discovery is a cover of "I Know It's Over" by the Smiths, a choice that is so obvious it's silly, given Buckley's Morrissey-like aesthetic, and a song he's far too much in awe of to really claim as his own.

No matter how familiar you are with an artist, it does that person a disservice to second guess what he or she might have done had they lived, and that's especially true of famously moody figures such as Smith, Drake and Buckley. Nevertheless, it's tempting to think of Smith smiling about fans taking pleasure from this worthy new addition to his catalog, while Drake and Buckley frown with even more misery than they displayed at their untimely ends.

ELLIOTT SMITH

"New Moon"

(Kill Rock Stars)

¼¼¼ ½

NICK DRAKE

"Family Tree"

(Tsunami/Fontana)

¼¼

JEFF BUCKLEY

"So Real"

(Columbia/Legacy)

¼