Last month marked the end of one of the great musical feuds of the 1990s.

Any Britpop fan knows you can either be a fan of Oasis or of Blur, but not a fan of both. The two bands hated each other's guts and were in constant competition throughout the decade. So all of us in the press were shocked when former Oasis guitarist Noel Gallagher joined Blur front man Damon Albarn onstage to perform for his Teenage Cancer Trust benefit concert.

Noel's brother and former Oasis singer Liam Gallagher is still no fan of Blur, nor of his brother. But it got me thinking about the eternal power of forgiveness.

Truly it seems that in the world of rock and roll, and wherever there's money to be made, all fences can be mended and all burnt bridges can be rebuilt. I decided to take a look back at some of the most historic feuds and their noteworthy ends.

5. The Eagles The Eagles had one of the most acrimonious break-ups in rock history, to the point where the band has commented they literally wanted to kill each other onstage during their last tour. They ended the whole thing in 1979 and embarked on solo careers. When asked when they would reunite, the reply was "when Hell freezes over."

So in 1994, when the cash called and the members felt like they didn't hate each other quite as much anymore, they jumped back on tour for one of the biggest tours ever; the appropriately titled live record was called Hell Freezes Over. The Eagles have been on the road ever since and even released a new album in 2007. Since 2001 alone, they've raked in $454 million dollars on tour and will be back for another outing this summer.

4. Jay-Z and Nas It all started in the late '90s, with the death of the Notorious B.I.G. Soon after a new king of hip-hop in New York would have to be crowned and it fell upon the genre's two brightest stars: Nas and Jay-Z.

The pressure was on them to compete from all sides. Then it started to get personal. By 2001, the two were firing shots back and forth through repeated diss songs, Jay claiming Nas was a fake and Nas insinuating Jay stole all his lines from Biggie.

The whole thing petered out in the mid-'00s and by 2006 the two were on good enough terms that Nas signed with Def Jam Records, which was then being run by none other than Jay-Z. For Nas' first release for Def Jam, Hip Hop is Dead, the two joined forces for a track called "Black Republican" that officially laid the feud to rest in musical form. They have since appeared together live and in many songs.

3. Paul McCartney and John Lennon The Beatles' breakup broke the hearts of teenage girls around the world, but it couldn't have broken the hearts of anyone more than the band members themselves. As good friends for many years, they were all just as crushed by the ultimate end of the band. Still, it was clear it was time for it to end. Tensions had mounted too much, particularly between the principal duo of Paul McCartney and John Lennon.

The potshots started almost immediately, especially from Lennon. In interviews, and even in songs like "How Do You Sleep?", Lennon repeatedly slammed McCartney and his musical talents. It seemingly killed the prospect of a reunion and led the media to make much of their "feud."

But in 1974, the two unexpectedly reunited in the studio for a jam session and immediately got on like old times. Unfortunately it was the last time they would record together before Lennon's death, and the session is a meandering mess, but it marked the end of what could loosely be referred to as a feud between the two old friends.