"Tom Waits'" latest melancholy blues fest begins with a collaboration with, of all bands, "Primus." "Big In Japan" features the loopy bass of Les Claypool, and odd guitar turnings of Larry LaLonde, backing up Waits' litany of everything he doesn't own and the consolation of popularity in the Land of the Rising Sun. As "Primus"-associated material is apt to do, the song sticks out from the rest of the offerings on the newly released "Mule Variations." The majority of the disc's 16 tracks consist mostly of sparse, haunting instrumentation, punctuated by Waits' gravelly voice. Lyrically, the songs largely reflect the somber tones of the music, with a few depressing tracks about sad, lonely people wandering aimlessly, another couple about guys reaching out for women they haven't got a hope in hell of attaining, and a couple of tracks that don't fit any easy category. One of the latter is "Eyeball Kid," about a disfigured kid that the protagonist is promising a shot at the Big Show. "He's just a little bitty thing/ He's just a little guy/ But women go crazy for the big blue eye/ They say how does he dream/ How does he think/ When he can't ever speak/ And he can't even blink." With a xylophone/ clarinet/circus-like soundtrack, and an auctioneer selling off rights to the title freak, the track is simply bizarre.

Another of the odd but endearing tracks is titled "What's He Building," an ode to nosy neighbors. Waits' spoken word delivers the perspective of a suspicious on-looker desperately trying to figure out, "What's he building in there?/ We have a right to know!" Set to Twilight Zone-ish noises, it's an invitation to neighborly paranoia.

The best tracks share a simple, straightforward and above all, a quiet piano/bass/drums, backing an unstrained, heartfelt vocal line by Waits. On, "House Where Nobody Lives," he offers a commentary about an empty house in a wavering, convincingly bothered voice, "Once it held laughter/ Once it held dreams/ Did they throw it away?/ Did they know what it means?" Similarly evoking the listener's pity is my favorite track on "Mule Variations," a Bruce Springsteen-style gem called "Hold On."

There's plenty to recommend about this disc, but this is one of those albums whose merits shift with the mood of the listener. If you're in a good mood, you probably wouldn't want to hear the depressing stuff on the album. On the other hand, if you're feeling a little bit low yourself, you might welcome Waits' music as a companion who knows your frame of mind. Then there's some material that's just too far out there to enjoy except in the most extreme moods, like the horn-blasted "Filipino Box Spring Hog." In the end, "Mule Variations" is a strange mix, offering a bit for every frame of mind, even as it remains firmly rooted in the blues.