In the beginning, there was music. Childhood and young adulthood floated by to a soundtrack of lyrics and rhythms and searing guitar riffs that consumed you, became you, constituted your identity, galvanized your intent, spoke your soul.

But time passes, classrooms fade to cubicles, and a vast landscape of new music turns foreign and unexplored. For Jeff Hersh, 31, the stereo came to double as Proust's madeleine, its purpose to invoke memories rather than create them.

"Finding music was easier when I was younger," says Hersh, a vice president at Smith Barney in New York. "In college I lived in a fraternity house with 70 guys all around me at all times, listening to various kinds of music. But as you get older, you work more, you get isolated."

Then in November, a friend told Hersh about Pandora.com, an inventive "Internet radio" website that generates music streams — "stations" — based on one's favorite artists or songs. He started his own private thread of music that was a combination of Neil Young and Pearl Jam, Hersh says, and in an hour he heard more new music he liked than he had in the last decade, much of it from obscure bands that shared musical traits with Young and Pearl Jam.

Despite wide-ranging concerns about getting older, most Americans want to live longer than the current average. But not too much longer. If it were up to them, Americans on average would like to live to be 87 years old -- nine years older than current life expectancy. But there's a limit: Just a quarter volunteer that they'd like to live to 100 or older. And even if medical breakthroughs made living to 120 possible, most would say no thanks.