The last thing anyone needs is another book about punk rock. Fortunately, Simon Reynolds thinks so too, and his book “”Rip It Up and Start Again: Postpunk 1978-1984″” avoids all the usual clichǸs of the genre by focusing on what happened after punk.

Dozens of books, articles, documentaries and VH1 specials have been devoted to punk, nearly enough to rival the libraries of literature on Elvis Presley and the Beatles.

The best book on the subject remains Jon Savage’s “”England’s Dreaming,”” which combines a shrewd social history of the U.K. in the ’70s with remarkable portraits of two of the movement’s major characters: scheming, manipulative Sex Pistols manager Malcolm McLaren and loud-mouthed yet sensitive Pistols singer Johnny “”Rotten”” Lydon.

Savage’s book ends where most of these retellings conclude – in 1978, when the Sex Pistols, punk’s most notorious band, broke up. But as Reynolds argues in “”Rip It Up and Start Again: Postpunk 1978-1984,”” the real story was just beginning.

After quitting the Pistols, Lydon started Public Image Ltd., a band that set out to be everything his old band was not. Influenced by dub, funk and disco, the group sounded nothing like punk – some people thought they didn’t even sound like music. But they set the stage for what came next.

Over the next few years, the British charts were filled with some of the wildest and strangest music ever made. To name some of the best-known bands – Gang of Four, Joy Division, the Fall, Scritti Politti and Wire – is merely to scratch the surface.

Free of the necessity to sound “”punk,”” with an enormous audience eager to hear something different, these bands could go in any direction. The results were, as Reynolds writes, “”a fabulous wealth of sounds and ideas.””

Some bands, like the Pop Group or Throbbing Gristle, made noisy, almost unlistenable records, as if they judged their success on how many listeners they could scare the daylights out of.

Others, like Young Marble Giants or the Raincoats, revolted against this new orthodoxy by playing quiet, eccentric, contemplative music.

By the mid-’80s, this short-lived renaissance had fizzled out, but its echoes could be heard everywhere in pop – especially on MTV, where many former postpunk bands (Human League, Devo, Depeche Mode) were finally getting their 15 minutes of fame.

Both stunningly well-researched (Reynolds seems to have read every single issue of every music magazine published in the U.K. between 1978 and 1984) and fun to read, “”Rip It Up and Start Again”” may be the best book anyone has written about pop music since “”England’s Dreaming.””

Reynolds, the author of “”Generation Ecstasy,”” an acclaimed history of dance music, has a knack for summing up a band’s sound in a single line: The bass on a Wire song, he writes, “”emits an unnatural glow, like fluorescent marble.”” The Fall summon up an image of “”sparks shooting out of a severed cable.””

In the past, Reynolds has sometimes gotten carried away by his own stylistic flamboyance. His earlier book “”The Sex Revolts,”” a study of gender in rock co-written with Joy Press, consists of virtually nothing but these little tongue-twisters of insight, making it an impressive but maddening read.

But “”Rip It Up and Start Again”” strikes just the right balance between history and criticism, between serious sociology and casual opinion-slinging.

“”Some people reckon the ‘true’ Slits sound is their early naive cacophony, the glorious racket of girls struggling with their instruments and vocal cords, impelled forward by sheer glee and gall,”” Reynolds writes of one of postpunk’s most notable acts, an all-girl gang who couldn’t play a note when they formed. “”Actually, the Slits got better when they got, ah, better.””

Whether you agree with everything he says or not, Reynolds is as well-informed a guide to this distressingly obscure era as you could hope to find.

Score: 10/10