Like CCM, Christmas music is defined by its lyrical content, not its music (though sleigh bells, chimes, and children’s choruses seem to be in every Christmas album from reggae to bluegrass). So, like CCM, it has spun off dozens of subgenres.

On one end of the spectrum are “seasonal” albums that make no reference to the birthday boy.

That’s expected from avant-garde jazz musician John Zorn’s A Dreamers Christmas [3 stars] since he usually makes “radical Jewish music.” It’s unsurprising on A Very She & Him Christmas [3 stars], a collection of standards from the M. Ward/Zooey Deschanel act that plays its ’60s nostalgia pretty straight. Jack Johnson’s indie compilation This Warm December Vol. 2 is has many strong original pieces [3 stars], but doesn’t have the nods to transcendence that 2008’s Vol. 1 had.

On the other end of the spectrum, by my count, worship albums outnumbered every other Christmas subgenre in 2011. Is it a reflection of the boom in worship music or an accurate reflection of how much of the Christmas story is worship (angels, shepherds, magi)?

Many of these albums are simply carols played live, as it the case with Christmas from the Vineyard [2 stars] or, remarkably, half of David Crowder Band’s Oh for Joy [3 stars] the band’s least creative effort to date (though, being Crowder, it’s still very good).

From the Belly of a Woman [4 stars], from the Seattle postrock/ambient group The Opiate Mass, is a live worship recording, too, but unlike any other Christmas album except 2009’s “Salvation Is Created” from Bifrost Arts. It’s not festive. This is not an album you’d put on in the background while hanging ornaments; it focuses attention on the mystery of the Incarnation.

Bifrost Arts’ “Joy Joy” makes an appearance on Sojourn’s A Child Is Born [4 stars]. The Louisville church band has made its mark collecting forgotten hymns and putting them to hard rock music that’s (supposedly) good for congregational worship. One would think it would be hard to extend that approach to Christmas music. But I’ve yet to find another album with John Newton’s “O Glorious Hour,” and hardly anyone sings as many verses of “Hark! The Herald Angels Sing.” Among the quieter tunes, meanwhile, is a nice cover of Bill Mallonee’s “Knocking At Your Door.”

Joy: An Irish Christmas [4 stars], from Keith and Kristyn Getty is the couple’s most Irish-sounding album yet (albeit heavily orchestrated: think Riverdance, not The Chieftains), incorporating traditional and original reels with traditional carols, rewritten Irish standards, and original Christmas hymns.

As long as we’re talking about music that’s popular among the Young Reformed crowd (Sojourn, the Gettys), Folk Angel’s Comfort & Joy [5 stars] is among the year’s best Christmas albums. The band, half of which is on staff at The Village Church (pastored by Matt Chandler) appears only to release Christmas albums: this is its third release, but its first full length album. Yes, it’s folky, with lots of banjos and even some musical saw, but its forays into rap and spoken word fit appropriately with its indie vibe.

But for the indie Christmas album of the year—no doubt the Christmas album of the year—you’ll have to look to Denmark. Hymns from Nineveh’s Endurance in Christmas Time [5 stars] features 13 original, intelligent, devotional tracks with no fluff. Like The Opiate Mass’ album, it’s a bit more of an Advent album, anticipating the Promise to set the world right more than jingle bells in the snow. But it’s beautiful enough to shuffle in with your Bing and Sufjan Christmas tracks, and it’s likely to stay in your mix after New Year’s Day.

The Christmas Hymns & Carols [3 stars] collection brings to mind 2002’s City on a Hill: It’s Christmas Time, and not just because it includes tracks from Derry Daugherty and Leigh Nash as well as unfamiliar artists. But ultimately it does sound like a various artists album more than a unified whole.

What separates a Christmas worship album from a Christmas carols collection, or a CCM Christmas release? With Phil Wickham’s Songs for Christmas [3 stars] it’s hard to tell, especially with the inclusion of “Have Yourself a Merry Little Christmas.” For the independent folk release Good People All, This Christmas Time [3 stars], it’s the claim on the cover but also celebratory reverence in the execution.

TobyMac’s Christmas in DiverseCity [4 stars] puts the spotlight on his band members to great effect as he steps into the background for the second half of the album. It’s clear that this album was not thrown together; it may in fact be one of his strongest.

The mix of original and traditional Christmas songs, using electronic, soul, funk, rap, R&B, and at least seven lead singers is skillfully cohesive. And the way the original songs address social issues without mawkishness is praiseworthy. This is the album that will “sound like Christmas 2011” when we’re feeling sentimental about it in a decade or two.