Olivia Newton-John Music Television. Michael Jackson. U2.

MTV went live on Aug. 1, 1981, with a flourish of self-important pronouncements about "revolution." But it took a few months for proof of the channel's game-changing potential to materialize-in the form of Olivia Newton-John's "Physical."

For her first record in three years, the reigning soft-rock queen aggressively tarted up her image: "Physical" is a disposable three-note hook surrounded by soft-porn come-ons. Compared with videos from just a year or two later-like Michael Jackson's "Billie Jean" (which began its seven-week run at No. 1 on March 5, 1983) or Michael Sembello's "Maniac" (No. 1 for two weeks beginning Sept. 19, 1983)-it looks prehistoric, homemade. No matter. "Physical" became a No. 1 hit on Nov. 21, 1981, and stayed atop the charts for 10 weeks-longer than any other song in the entire decade.

Every musical decade is sooner or later reduced to a sweeping generalization. We know the '60s weren't all about peace and love, but that's the tag. The '80s? It was a moment of big and bigger.

Fans became accustomed to a dizzying new set of marketing contrivances-if there's a poster act for this glitzed-out decade, it's Milli Vanilli, the duo whose three No. 1 hits ("Baby Don't Forget My Number," "Girl I'm Gonna Miss You" and "Blame It on the Rain") were tainted with an asterisk after it was revealed that Fab Morvan and Rob Pilatus didn't actually sing on the tracks.

A sure route to chart success was to play the "Physical" game, ginning up sexy or controversial or ironic visuals to sell otherwise unremarkable tunes. How else to explain the success of post-disco Hall & Oates, whose dopey "Maneater" spent four weeks at No. 1. Toni Basil's "Mickey" falls into this category, too. And even venerable songwriter Billy Joel's nostalgic exercise "We Didn't Start the Fire" fits in. Would that have hit No. 1 without its intense video?

Megawatt marketing became an '80s fact of life, but it wasn't the whole story. It was also the decade of radical rhythm upheaval-musicians exploring new blends of rock and R&B and funk. It's the decade of Michael Jackson, whose "Thriller" remains a high-water mark not just in terms of big sales, but as an example of deep and enduring creativity.

The '80s stand as a time of striking diversity on the charts-during one stretch in 1980, the No. 1 spot was owned by Pink Floyd ("Another Brick in the Wall Pt. II"), then Blondie ("Call Me"), then Lipps Inc. ("Funkytown"). Shortly before "Physical" erupted, the nation's biggest song was "Endless Love," a duet from Diana Ross and Lionel Richie that was the first in what became a decade-long string of squishy love duets; a few months after "Physical" petered out, Joan Jett & the Blackhearts roared into view with "I Love Rock and Roll," (No. 1 on March 20, 1982), which eschewed the coy in favor of super-clear declarative blast.

The craft and discipline involved in writing a hit song didn't suddenly become obsolete-rather, songs that stand as shining examples of craft, such as Foreigner's "I Want to Know What Love Is" (No. 1 for two weeks in February 1985) had to vie for attention alongside slight tunes like Ray Parker Jr.'s "Ghostbusters" that prevailed as a result of disproportionate MTV love.

The '80s were a time of gaudy crap in every possible hue. But for every "Physical," there's a song like the stirring gospel confessional "I Still Haven't Found What I'm Looking For," U2's second No. 1 single from 1987's "The Joshua Tree": "I have spoke with the tongue of angels/I have held the hand of a devil/It was warm in the night/I was cold as a stone." If this is the epitaph for the decade, the '80s are worth their weight in lamé-and actual gold.