I can't remember the first song I learned to play on bass, but the first song I learned to play on guitar was 'For Your Love' by the Yardbirds. That kind of was the beginning for me. I thought it was a great song and I loved the open chord progression at the beginning of that song.
I've never been one that thinks that the function of an instrument is to approach the purity of voice or the structure of a beautifully sung line.