As much as I like Led Zep, they blatantly stole tons of songs. Everything from Delta Blues, to old Irish folk songs were copied word for word, and maybe one word in the title was changed. Sometimes when the real writer complained they fessed up and gave credit, but it usually took a bunch of lawsuits. Recently I was listening to a DJ that spent an entire Sunday afternoon playing the original songs, then the Led Zep version. It was eye opening how many of their most famous tracks were stolen. Of course Led Zep did them better, but forget about them being great songwriters.