Music fans are increasingly watching live concerts without gassing up cars, driving to venues, or paying for expensive tickets and convenience fees. Music webcasting has shown promise for over a decade, but the stage is being set now for an online live-music renaissance.

YouTube webcast its first-ever live concert last Sunday: U2 at the Pasadena Rose Bowl. It brought in 10 million viewers worldwide in addition to the 100,000 who attended in person. A spokesman said that makes it the biggest event in the site’s history.

Billboard followed suit with the launch of Billboard Live. Sony has big plans to beam shows to its movie theaters over satellite, and interactive features are bringing online viewers closer to the mix, and sometimes into the mix.

Live music and digital music are opposite sides of the same coin. People listen to digital music alone, while concerts are about physical proximity to musicians and the crowd. Developers are finding a new middle ground, although it took a little longer than some of us thought.

The audience for live o