John Lennon. I'm not going to link anything here - if you can't find Lennon material online, you're really not trying.
I've done a fictionalised version of this already, but it will bear a little repetition. One early December morning in 1980, I awake as usual in my spartan room in Cowan House (You'll notice, if you follow the link, that it's recently been demolished. I managed not to shed a tear...) I turn on the radio, and am surprised to hear two Lennon tracks in a row, followed by the kind of silence which tells you everything you need to know. The subsequent news bulletin is still a little sketchy in the details, but there's no doubt about what has happened. It's the first time I have been affected so strongly by something since I left home; indeed, it's probably the first time I have been affected so powerfully by anything. I can't claim that he was one of my heroes, or that I had any particular link to him or his music, but this was a seismic event nevertheless. The conversation and the news bulletins were dominated by it for what seemed like weks afterwards - probably only a few days, in reality, and the music charts were full of Lennon for months.
And that's what I really remember, I suppose - that Christmas period full of 'Imagine' and 'Happy Xmas, War is Over'; Bryan Ferry crooning 'Jealous Guy' and those wire rimmed glasses staring out from every record shopfront. I suppose that in some strange way, the 8th of December 1980 marked an end to my innocence - it's glib to say that nothing was the same again, but nothing really was, after that.