IN THE cold light of 1999, it's easy to forget that reggae was once the hip-hop of its time, a well of indigenous black music used by every other mainstream act as a source of rejuvenation and inspiration. Survey a list of such '70s-somethings and marvel: The Rolling Stones, Eric Clapton, The Boomtown Rats, The Clash, The Police, Serge Gainsbourg, Grace Jones - even Bob Dylan and Led Zeppelin had sporadic flirtations with the form. 20 years ago reggae was it.

This compilation is the fifth in the Island Records 40th-anniversary series, and the period it covers is pretty crucial, beginning with the 1972 US release of Jimmy Cliff's classic film (and tune) The Harder They Come, acknowledging the success of Bob Marley And The Wailers over the next decade, and concluding with the genre's subsequent mutations into pop crossover chart action with the likes of Chaka Demus ... Pliers in the early 1990s.

However, Volume 5 can't claim to be a comprehensive collection, for there are glaring omissions. For instance, the snubbing of Linton Kwesi Johnson in favour of Aswad's diet-lite 'Don't Turn Around' is an inexcusable oversight. That said, the first half hour of the record is the Dread Beat An' Blood of any party, boasting classics like Junior Murvin's 'Police And Thieves', Dillinger's wicked 'Cokane In My Brain', and Gregory Isaac's 'Night Nurse' (recently repainted by Mick Hucknell with Sly and Robbie).

But there's also a deeper, darker class of dub war going on, such as Toots ... The Maytals appropriation of James Brown raunch in 'Funky Kingston'. Indeed, fast-forward to '95, and you'll find Buju Banton employing similarly bad-assed vocal tactics on the ragga-centric 'Champion'.

The real treasures are the ones most deeply buried in the mix. For proof, cop an ear to the hallucinogenic toasting of Lee 'Scratch' Perry (the Beam-Me-Up-Scotty of the studio-shacks, boosting impossible innovations out of the most rudimentary four-track facilities) as he bellies through 'Roast Fish And Cornbread'. Similarly, the proto-drum 'n' bass shadowplay of Augustus Pablo's 'King Tubby Meets The Rockers Uptown' is some funky shit - if your anatomy doesn't vibrate to this frequency, you're dead from the neck up.

Of course, it can't all be as good: acts like Black Uhuru and Third World were to be found paddling in the shallows of the music rather than diving for pearls, but there's enough good stuff here to seriously road-test any subsonic sound system. Check it out.