A shaggy dog story: Tom Waits shows up at a Northern Californian studio, prospecting for premises close to home so that he can ferry his kids to and from school while working. The in-house engineer duly gives his guest a guided tour of the facility. "Here's where we record the drums," he says, indicating a carpeted cell. "Yeah, yeah, we'll try it for a while," the singer growls before disappearing out the back of the building. Twenty minutes later, the tech finds Waits crawling around in a chicken coop in the yard, belly up in bantam-shit, banging slats of wood together and cocking his head to gauge the acoustics.

Green On Red guitarist Chuck Prophet once related this tall tale to the present writer, and if it ain't true, it should be. See, Tom Waits, to paraphrase Mickey Rourke in Angel Heart, has a thing about chicken coops: Mule Variations, his first album in six years, was recorded in Prairie Sun Recording Studios, a converted fowl-house in Sebastapol.

But then, Waits hates conventional sonic configurations, the production-line furniture of rock 'n' roll; drumkits, Marshall stacks, wedges, lighting trusses and sterile studio set-ups. Here's a rock 'n' roll primitivist who won't think twice about replacing a thousand dollar bass drum sound with the slamming of a toilet lid, preferring his source noises not so much rare as raw and bloody. Accordingly, this new selection continues to uphold the credo William Burroughs croaked on The Black Rider in 1993: "It ain't no sin to take off your skin/And dance around in your bones".

However, Mule Variations has more in common with Bone Machine than that last sulphurous symphony, incorporating the caveman blues of Huddie Ledbetter, Captain Beefheart and Howlin' Wolf. This is music that doesn't bother wiping its feet at the door. And despite the adoration of the many young bucks (Gomez, Mercury Rev, the No Depression-ites) who sit at his muck-crusted workboots, Tom has more kinship with the dope-talk and prison rhythms of hip-hop, the present day equivalent to the coded black vernacular of the chain-gangs. Indeed, the singer was forging his own proto-gangsta rap as far back as 1983 on tracks like '16 Shells From A 30.6', a strain still evident here in the clanking consonants and boiler-room hiss of 'Filipino Box Spring Hog'.

Anyway, MV is a record of at least two minds; scuffed rooming-house madrigals ('Lowside Of The Road', 'Cold Water', 'Pony') contrasted with big, fat, bleeding heart ballads ('Picture In A Frame', 'House Where Nobody Lives'). Here are songs about the sadness of empty abodes, the heat of hog-horniness, dreams gone mouldy, the lure of the hearth. And, as if for the first time, we can hear what an amazing voice Waits has got. Folk who reckon Toni Braxton is the last word in vocalese might haul us all off to the nearest red-brick building for propounding such a view, but listen to the grain, no, the ridges in the vocal chords as he tears lines like "Why wasn't God watching?" out of his chest on the agonising child-murder ballad 'Georgia Lee'.

Less harrowing is the opening music biz piss-take 'Big In Japan', where the vocalist sounds like he's enunciating through a smoker's throatbox (it was rumoured he'd been afflicted with throat cancer). Either way, one is tempted to imagine Otis Redding, if he lived to hit the skids, spending his days hollering tunes like 'Hold On' or 'Take It With Me' for spare change.

Waits has been using the word "surrural" to describe the field he's currently potting crows in ('Chocolate Jesus' was recorded outdoors - you can clearly hear the breeze and the traffic), and it's as good a one as any. You don't have to be country to understand his bog-warped humour, but it doesn't hurt. Take 'Eyeball Kid' for example, a mutant showbiz sprog "born without a body/Not even a brow . . . He's just a little guy/But women go crazy/For the big blue eye".

Elsewhere, 'What's He Building?' parodies parochial paranoia (recalling Burroughs' dry observation of America as a country "where nobody is allowed to mind his own business" in his 'Thanksgiving Prayer'). Over waves of wireless noise and what sounds like a musical interpretation of Japanese water torture, the narrator growls, "Now what's that sound from under the door?/He's pounding nails into a hardwood floor . . . he has a router and a table saw/And you won't believe what Mr. Sticha saw/There's poison underneath the sink of course/But there's also enough formaldehyde to choke a horse . . . What the hell is he building in there?"

Mostly though, it's an emotionally forthright record, due in no small part to Kathleen Brennan's co-writing/production labours and textures like Charlie Musselwhite's blues harp on 'Get Behind The Mule'. There's also sterling work from Tom's long-term skeleton crew: Joe Gore, Greg Cohen and that half-man/half Gila monster Marc Ribot, who, on evidence of his solos in 'Black Market Baby' ("There's no prayer like desire/There's amnesia in her kiss") and 'Cold Water', still plays guitar like he's got hacksaws for hands. And I mean that as a compliment.

If the stunning cover art and the songs on this record (particularly the convivial Billy Goat Gruff stomp of 'Come On Up To The House') are anything to go by, Uncle Tom is becoming a comfortable kind of old scarecrow. Welcoming as it is though, Mule Variations is unmistakably Waits' world. We're just renting head-space in it.