Frank

It doesn't happen often, but every now and then a band comes out of nowhere with a sound so new, so captivating that the musicians making the music become icons, legends. Then comes the avalanche. The same sound that made the band famous becomes stale, old and repetitive. The same structure that was once so liberating is now confining and the same ambition or creative drive that fueled the band becomes self-consuming.

Or they sell their songs to CSI, Cadillac or Buick.

With that in mind, here's seven bands that should have quit while they were ahead:

U2: It's hard to remember a time when U2 were more than just fertile ground for parody, but it does exist. Boy is optimistic and introduced the stadium rock sound the band would become known for in the 80s. October is a spiritual record, full of quiet moments that say just as much as kinetic songs like "Rejoice" and "Gloria."

Critics tout the overrated The Joshua Tree and Achtung Baby as the band's legacy, but War is their best record, a perfect combination of radio-friendly tracks like "New Year's Day" and anonymous anthems like "Red Light" that still sound good today. It was also the last time the band sounded earnest in their politics rather than the pompous know-it-alls they've become since.

Sure, their follow-up, The Unforgettable Fire, yielded one of their most memorable songs, "Pride (In the Name of Love)," but it also signified the beginning of the band's journey toward self-importance and eventual self-parody that culminated with 1997's Pop.

In a perfect world they would have hung it up after Achtung Baby, a good record with plenty of solid hooks and newfound swagger. The principles and self-importance they ran into the ground on The Joshua Tree are still present, but only around the edges.

The Rolling Stones: A lot of people don't know this, but The Rolling Stones died in a fiery plane crash just after completing their masterpiece, Exile on Main St. The people making music in their wake are actually undead versions of the Stones, brought back to life by the ghost of Aleister Crowley. How else can you explain Keith Richard's inability to succumb to the daily rigors he puts himself through?

In all seriousness, if Mick and the boys had met an (un)timely end after Exile we wouldn't have "Start Me Up," "Miss You," "Beast of Burden" and "Angie." But we also wouldn't have Tattoo You, "Anybody Seen My Baby," Freejack and this little gem.

Led Zeppelin: People often cite John Bonham's death as the end to Led Zeppelin, but after Physical Graffiti, The Song Remains the Same, Presence and In Through the Out Door, the band was already on pretty shaky ground, especially considering the last two.

Even Paige and Plant acknowledge this. They rarely play songs from their mid-1970s output live and the recently released, Paige-remastered Mothership features multiple tracks from the band's early work, while only a single song represents each of their later albums.

It's just too bad they didn't walk away after the stellar Houses of the Holy. After all, it's that era of their catalog fans most celebrate. And while the band did get more expansive and experimental, the results were often iffy. Their early work has a focus that their later work lack and when they were firing on all cylinders in the early 70s, they were a force of nature.

Metallica: Remember Metallica in the 80s? Remember how much ass they kicked in their unkempt mullets and sleazy facial hair? They were speed metal at its finest —fast, ugly, raw and aggressive — the musical equivalent of an I-ROC Z28 convertible with the seatbelts ripped out to make it extra dangerous.

Now the band is more like KIA Sedona, complete with side-impact airbags and a five-star safety rating. Their self-titled Black Album is their magnum opus, an album that is simultaneously exploratory and familiar; loud and melodic, it contained all the elements that made previous albums great, but was in no way a retread of familiar territory.

If they had broken up after this album they would have become legendary, in a way that is only attainable through a perfect track record and an unexpected departure.

The Who: When talking about bands that hit their peak and then chose to ride the wave into the ground, instead of bailing out while they were on top, it's hard not to mention The Who.

Pete Townshend brought a level of sophistication formally unheard in British rock music. Roger Daltrey was an all-to-willing face for the burgeoning Mod movement. While the Beatles wrote about love and being in love and The Kinks wrote about everything, The Who wrote about longing and insecurity. Also amphetamines.

Then, when they could have easily followed the same formula, The Who got experimental. The Who Sell Out sees the band muddle with psychedelia on tracks like "I Can See For Miles" and then Tommy was melodic, conceptual — and ambitious to a fault.

But without Tommy (and Townshend's breakdown during his next rock opera, Lifehouse) The Who's landmark Who's Next would not exist. Equal parts quiet introspection and thunderous power, Who's Next captures one of the world's greatest bands in top form.

And it was all downhill after that. Quadraphenia lacked focus, but contained a handful of good tracks, most notably "Can You See The Real Me" and "Love Reign O'er Me." Who Are You was tired and scatterbrained.

But it was band's decision to continue making albums after the death of a principle member that sealed their place on this list. Keith Moon was such a personality on their records that his absence was noticeable immediately.

Of course, it didn't help that they fell into the synthesizer pitfall that snared so many bands in the 80s.

Guns N' Roses: While Nirvana got a lot of credit for effectively destroying hair metal, GNR did more than their fair share with Appetite For Destruction, an excellent hard rock album without a bad song on it. Guns N' Roses were subversive. They looked like bands such as Poison or Motley Crüe, but played music more akin to the Motörhead or Metallica crowds.

Appetite is focused, aggressive and mean from top to bottom. The opening track "Welcome To The Jungle" serves as a mission statement for the entire album, and Slash's guitar playing was never better.

It's ironic that the success of Appetite For Destruction turned the band — or at least Axl Rose— into the same self-indulgent assholes they helped kill off. Post-Appetite GNR reached critical mass on "November Rain," a song so bloated, drawn out and senselessly-epic, it disappears up it's own ass four minutes in — and then goes on for another five.

Stopping after Appetite would have avoided this, but given Axl's latest offering Chinese Democracy, an album that has taken almost 10 years and more than $13 million to make, but has still not seen the light of day, he seems intent on making the same mistake.

The Wu Tang Clan: Yes, Wu Tang. Enter the Wu Tang: 36 Chambers is one of the best albums on the 90s, possibly the best. It features impeccable production courtesy of The Rza and the kind of swagger usually reserved for rock stars. Like many of the albums on this list, "Bring Da Ruckus" is an album-defining anthem that sets the stage for the organized chaos to follow and "C.R.E.A.M.," "Protect Ya Neck," and "Wu Tang Clan Ain't Nothin' To Fuck Wit" are still crowd favorites. But the album's greatest accomplishment is its ability to give a voice to each of the nine members.

If anything, the clan created a monster. 36 Chambers is so good, that it dwarfs everything the group has done, either together or apart. The RZA has written soundtracks produced several side projects. He, along with Method Man, ODB, and Ghostface sold millions of solo albumes, but they individually can't compare. Even Wu Tang's excellent The W is eclipsed.

Because of this, and the fact that many of the members used Enter The Wu Tang: 36 Chambers as a springboard to solo stardom, maybe the clan should have just stopped after one amazing album. The 36 Chambers would have served like hip hop equivalent of the monolith from 2001: A Space Odyssey — a towering thing of beauty that signified the dawn of a new age and puzzled its forbearers.