U2 started as a cover band. They'd learn poor renditions of other artist's songs, climb on stage and shred away in front of an audience that had never heard the violent beauty of an electric guitar. One day, they traveled sixty miles to the small Irish town of Mullingar where they played their covers. After the show, they were cornered by a local who said, "If we wanted to hear cover versions, there are plenty of bands around here who can play them just as badly." After this confrontation, U2 decided to start writing and playing their own original material. Copying other people's work is an effective way to learn a craft. But, it's a piss poor means of leaving behind a legacy.