Jackie-O Motherfucker - Fig. 5 (2000). Many reviews of Jackie-O MF's music mention Captain Beefheart, and he's an appropriate antecedent, even if you couldn't mistake Fig. 5 for a Beefheart album by any means. Jackie-O MF has an eclectic and catholic take on American music, incorporating everything from old blues and folk music to free jazz to surf/garage rock to trance-like post-rock. There's a definite similarity to fellow skronk-Deadhead band Akron/Family, although it's also safe to say that neither band sounds that much like the other, but they're definitely cousins of sorts.
The Jackson Five - The Jackson 5 Christmas Album (1970) and Greatest Hits (recorded 1969-1971). I admit it. I'm a sucker for the J5's bubblefunk. The Xmas album is overwhelmingly treacly, but the Greatest Hits (released two years after the J5's debut with five released studio albums under their belts - actually four, subtracting out the unrepresented Xmas album) is great. Well, the first two singles, "I Want You Back" and "ABC," are freakin' great, and the others are okay-to-good, but they look better for their proximity to the first two singles.
Jaco Pastorius - Come On Come Over: A Jaco Pastorius Compilation (2-disc comp made by my pal Randy Porter circa 2003-ish), Jaco Pastorius (1976), Word Of Mouth (1981), and The Birthday Concert (1982). Pastorius was, of course, an amazing bassist, one of the best who ever lived, a guy with a conception of the instrument that was remarkably different from just about anything that came before. He was also the root of some very bad self-indulgent music, especially in his followers, but I think his output nets positive. The first of these, my friend's compilation, features a number of tracks of Pastorius as a sideman, often including audio testimonies about how Pastorius affected the people he played with. I'm not crazy about Weather Report, the fusion band Pastorius played with in the late 70s, but some of these tracks are definitely amazing. I'm also not crazy about Joni Mitchell's jazz period, when Pastorius was the main musician on her albums, but again: yes, that guy could cook. I like his first, eponymous solo album quite a bit. I mean, I could do without the flute-driven "(Used to Be A) Cha-Cha," but the krautrock-meets-electric-Miles tracks "Okonkole Y Trompa" is a mind-blower. The more big-band oriented Word of Mouth is okay, but not quite as interesting. And there's lots of good to be found on The Birthday Concert, another big-band outing, but the music sometimes - unfortunately - resembles the Saturday Night Players warming up the crowd before the guest host takes the stage. Not long after this was recorded, Pastorius's life was taken over by untreated bipolar disorder and alcoholism, and within five years, he was dead at the hand of a redneck club bouncer in South Florida.
Jacob Miller - Who Say Jah No Dread (recorded 1974-1975). One of the great voices in reggae, as produced by Augustus Pablo and remixed into dub form by King Tubby. Wow! This is first-rate reggae, almost as good as the Congos' Heart of the Congos or Culture's Two Sevens Clash. Sadly, Miller's career was cut short by a car accident some 5-6 years later in 1980, when he was only 27.
Jaga Jazzist - The Stix (2003). With its electronics and horns and noise, I've always placed Jaga Jazzist into the fake-jazz "post-rock" genre, where resides Tortoise and similar fake-jazz bands. But I think one could argue (and, indeed, many do argue) that Jaga Jazzist is closer to real avant-jazz, as re-interpreted in the age of noisy rock. To be fair, I don't think post-rock is fake jazz, but a blend of jazz and rock (and noise and electronica and even, god help us, lounge). So I'm not sure that the genre concern is that large for me. But that's what this music is: interesting, intellectual, challenging, and a pleasure.