All there is to know about everything: Anyone for eight hours of Metallica? Andy Gill assesses the latest crop of boxed sets, from Steely Dan to Brian Eno via Otis Redding

If, as the analysts tell us, we really are in the grip of a post- Christmas retail frenzy, then perhaps this is the year that you might actually give in to temptation and splash out on that gleaming multiple-CD box set beckoning so teasingly from the high shelf of your local record shop. What could possibly be more festively indulgent than shelling out around fifty quid for the collected works of somebody whose collected works you probably already own, albeit only in pathetic single-disc portions?

For obvious demographic reasons, most such career retrospectives concentrate on the dead or otherwise departed. If you so desired, for instance, you could swallow whole the entire output of Steely Dan on Citizen Steely Dan 1972-1980 (MCA MCAD 4-10981), though such an excess of rich musical fare - not to mention irony, sarcasm, wit and downright cynicism - would be sure to bring its own digestive problems. Since, sales-wise, Steely Dan have been one of the best posthumous back- catalogue performers of the CD era, it seems unlikely that their market hasn't already reached saturation- point, but for those whose association with the group is fragmentary, here is a useful opportunity to acquire one of the most consistent oeuvres of the pop era.

Perhaps Steely Dan's greatest innovation was the triumph of head over heart in their work, as the cool, cynical Seventies supplanted the naive aspirations of the Sixties: no superfluous sentimentality stains their work, which places it in pointed contrast to the superficially similar - intelligent, musicianly, jazz-inflected - style of the Police, whose Message In A Box: The Complete Recordings (A&M 540 150-2) is just what it says: all the albums and a bunch of out- takes, B-sides and soundtrack numbers crammed on to a four- disc limited edition set. (My copy is numbered somewhere in the 139,000s, so a certain strain is being placed here on the notion of limitation.) Compared with Steely Dan, the overall effect is of being washed away on a tide of ersatz emotion.

If it's genuine emotion you're after, you'd be better off investing in OTIS] - The Definitive Otis Redding (Atlantic/Rhino 8122- 71439-2), a four-CD set which outdoes all previous compilations in covering the Georgia soulman's career, filling in gaps with his earliest material, on which the debt to Little Richard is more noticeable. It includes everything of note from 1962's 'These Arms of Mine' and 'Pain in my Heart', which defined his classic deep-soul style, through the stunning Otis Blue period - when he could dash off a half- dozen masterpieces in a single day's recording - to the perfectly elegaic 'Dock Of The Bay'. For good measure, the fourth disc draws together classic live performances from various stages of Otis's career, complete with evocatively 'groovy' introduction from the Emperor Rosko.

Paul Simon 1964 / 1993 (Warner Bros 9 45394-2) is not as exhaustive, cramming a long career, stuffed with quality merchandise, on to a measly three CDs packaged, in coy deference to the songwriter's literacy, to resemble a book. His time with Garfunkel is rushed through in barely a dozen tracks, some rendered solo, and among the necessities left out are 'Homeward Bound', 'I am a Rock' and 'Scarborough Fair'. Since the third disc is given over completely to the Graceland / Rhythm of the Saints period, that leaves a lot of mid-period solo gems squeezed on to the second disc. It's no real improvement on earlier compilations, despite being tricked out with a handful of bonus tracks including a solo demo of 'Bridge Over Troubled Water' - Simon straining for Garfunkel's range - and the comic sketch, 'The Breakup', in which Paul gives Artie directorial coaching in vocal sincerity as the latter announces their split.

That other diminutive genius Brian Eno, presumably asserting the essential left-brain / right-brain duality of his work, has not one but two boxes on offer - the ambient- orientated Instrumental (Virgin ENOBX 1) and pop-orientated Vocal (Virgin ENBOBX 2), each comprising three digipacked CDs and a fourth fake-digipack with a long essay and all the relevant track information. The two boxes tell their own tale of his career: the Vocal box focuses tightly on his Seventies work, his singing withering away into an occasional pastime by the third disc, while the Instrumental box begins a few years later and expands, in appropriately oceanic manner, to consume most of his attention through the Eighties, even as the ambient pieces themselves grow paler and more insubstantial. The packaging is, as you'd expect, pleasingly artful: the plastic racking inside the slip-cases which holds the individual discs separate renders them reminiscent of circuit-boards.

As far as packaging goes, though, it would be hard to beat Metallica's Live Shit: Binge And Purge (Vertigo 518 725-0), which comes in a hefty imitation flight-case stencilled with the group's logo. It's impassively impressive, built to withstand nuclear holocaust at the very least, and heartily indicative of the rolled-sleeves work ahead, which for the listener involves ploughing through a succession of live shows totalling well over eight hours. As such, it's aptly titled: the doughty metal-heads strong-willed enough to binge their way through the package's three CDs and three videos at one sitting are very likely to end up purged of the desire ever to hear the group, or indeed music, again. It does, however, succeed admirably in its presumed intention of placing Metallica - despite the rival claims of such flashier, back- combed bad boys as Guns N'Roses - on top of the heavy metal heap, equally adept at the darker, moodier metal modes as at the thrash- metal they helped originate. But seventy quid? That's an awful lot to purge in one go.

The best genre compilation currently available is Tougher Than Tough - The Story Of Jamaican Music (Mango IBXCD 1), whose scrupulously assembled chronology spreads across four discs. The first two discs are exemplary, taking us from the pre-ska R&B of Laurel Aitken, through the various subtle changes of rhythmic emphasis - blue beat, rock steady, reggae - and covering all the main styles and sub-genres along the way, from pop to toasting to pop-up toasters. The third disc makes a decent fist of disguising the decline of reggae in the late rasta era, as it drifted into the Eighties on a cloud of ganja smoke, though the absence of such monumental figures as Augustus Pablo and (especially) dub pioneer King Tubby is unforgivable, and could have been easily rectified at the expense of some of the tiresome ragga and dancehall cuts assembled on the last disc.

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