My dad's favorite singer/songwriter in the whole wide world is Gordon Lightfoot. In fact, we actually got backstage passes and met him at a concert in 2009. I think my dad could have died happy as we left to go home.
Eva Cassidy's version of his song is so achingly beautiful that it makes me want to get better at guitar so I could play it.
(sorry for the weird images in this YouTube video - it's the only version I could find)
"Early Morning Rain" - Eva Cassidy