He was a year younger than Lennon.
Of course, it was his own fault; he was a lousy driver.
I was in shock when I heard John Lennon died, but the passing of Steve Goodman, Kate Wolf, and Eva Cassidy saddened me tremendously as I had met each of them and was a big fan.
Lennon for one, because I was a freshman in college, and had just read his Playboy interview the week he died.
Elvis, because I was a big fan between the ages of 12-17.
Stevie Ray Vaughan probably hit me the hardest though, because I was really appreciating his music and his life. It seemed so sad that he was clean and sober, then died in a helicopter crash.
I was 16 when Otis Redding died in that plane crash. It shook me so badly that I ditched school to drive down to Macon to attend his funeral. I know I’ve written about this before, but the only refernce to it I find when searching is here.
Later, Duane Allman’s death shook me, bucause it was as though I had grown up the band, watching them countless times play free concerts in Atlanta before they finally hit it big. I think a lot of it had to do with how eerily similar Duane’s death was to Otis’s (both just hitting the big time, both from Macon, both managed by Phil Walden).
Lennon’s death shook me to the core, but only Otis’s moved me to the point that I had to pay last respects.
Elliot Smith was one of my favorite musicians when he died, but it’s wrong to say he had the biggest effect since Kurt Cobain was so huge when he died. I didn’t even care for Nirvana that much, but his death was huge. Of course, everybody assumed I thought Nirvana was the greatest band on earth, but I was too cool to listen to such plebeian music. 
Michael Hedges, by far.
Bob Marley. I don’t think the death itself saddened me so much at the time, but it did influence my interest in reggae music, which I had just begun to explore, and became a huge fan of since.
Henry Purcell.
Agreed
There are only a couple of musicians per century whose compositions consistently take my breath away. Mankind should be forever indebted to them, not simply for being born exceptionally gifted musicians/composers/virtuosos, but for having the force of character to give heart and soul to their craft and dare to be the paradigm shifters. My short list includes: Johann Sebastian Bach, Wolfgang Amadeus Mozart, Ludwig van Beethoven, Franz Liszt, Sergei Rachmaninoff and John Lennon.
The music died for me when Lennon died.
…well, there is John Tesh…I kid 
Harry Nilsson, too young and I’d love to have seen him produce more.
Randy Rhoads, a rare speed-shredder that could also play with feeling and soul.
Johnny Ramone
This. I was making a mix CD of his stuff when I found out. I was crushed.
I was going to say Harry Chapin as well. He was funny, talented, and generous to a fault. He died on July 16 and I had tickets to see him on July 22. (I was fortunate in that I was able to see him in concert once before that.)
Also, Dave Carter of folk music fame. He wasn’t particularly young (49, I think), but he was just gaining traction in his career with the albums Tanglewood Tree and Drum, Hat, Buddha when he died. Brilliant writer.
Joe Strummer
The first one I remember was John Lennon. I think I was 11. I already knew the Beatles and Lennon’s solo work because my mom was a fan. She was very upset and that upset me.
As far as affecting me personally, I would have to say Kurt Cobain.
I love this story.
It wasn’t profound, but John Lennon’s death shocked me. I was at home, writing a paper for finals, but instead of working, I was glued to the radio all day. But I cried for George Harrison. His song, All Things Must Pass, still sums it (Life, the Universe, and Everything) all up for me, and is a song I play whenever I have a loss to mourn.
Probably one else will say this (or know who he is), but Keith Green. Green was a major influence on modern Christian music, coming on the Jesus movement of the 1970’s along with guys like Larry Norman and Randy Stonehill. He wrote catchy tunes with humorous and confrontational Christian lyrics, and was a major influence on contemporary Christian music for entire generation. Then in 1983 at the age of 28, Keith and two of his four children were killed in a small plane crash.
I was 13 at the time and a big fan of Green’s music. I was pretty heartbroken for a while. His biography written by his wife (No Compromise, I think) is worth reading.
While Jim Morrison’s death was the one that shocked and saddened me the most, John and George are the only celebrity/public figure deaths that ever brought tears to my eyes.
.
I called and broke the news of Elvis’ passing to my mother. She was hit pretty hard.
And I know it’s not musicians, but I actually cried when John Ritter died, too (same day as Johnny, if I recall correctly.)
Kurt Cobain, by far.
I didn’t like music as a kid, which surprises a lot of people. There wasn’t any music I liked well enough to want to own until I was in 9th grade: Nevermind by Nirvana and Blood Sugar Sex Magik by The Red Hot Chili Peppers were the first two albums I ever bought myself…and all of the sudden I got it, I finally understood what it was that people liked so much about listening to songs. That music opened a lot of doors for me fairly quickly. I’d bought as much music by both as I could by the time I was almost 17, and my friend Dawn and I were working on a plan to convince our parents to let us see them if they came anywhere near that summer. Then, less than a week before my birthday, the news arrived that Kurt was gone 
By this point there are a number of bands I wish I’d seen before they broke up, but none of them make me as sad as never having gotten the chance to see Nirvana live.