5. Led Zeppelin - 'Physical Graffiti'
Led Zeppelin found themselves with a little problem near the end of the Physical Graffiti sessions in 1974. They had eight songs they absolutely loved, but they couldn't all fit onto a single album. They didn't want to record more songs just to pull off a double album, so they combed through their vault and dug out enough songs to fill out the second record. The outtakes fit in seamlessly with the new material and few fans even knew the true story behind the album. They just knew the new Zeppelin album was the longest one yet.