Clair de lune, by Claude Debussy:
Claire de lune simply is a beautiful song, I adore it. It's impact is strengthened by the lifetime of association I have with it. My late Grandmother used to play it (she was an accomplished pianist and singer) and I used to hear it a lot in general, whether it was my Mum playing it on CD or just hearing on the radio. I heard the song a few months back for the first time in a year or so and was taken by how beautiful it is, then when I watched that video I was truly lost and fighting back tears. When I hear this song I think of my Grandmother and my Mother. Claire de lune is the most beautful song I've ever heard.
This leads me to music and how it can take you back to the past. When I listen to System of a Down I think about many things - HELD was in its adolesent prime, and Smash Bros Melee was all the rage, and apparently jew fros were too. SOAD doesn't just bring back one specific memory, but memories of a time, of a period of my life - and that is very powerful.
What songs take you back?