“The Internet is seizing the spotlight in the live-music business — again. A dot-com-era bid by concert promoters to market live gigs online fizzled out. But now concert Webcasts and vintage performance clips are gaining new currency. An array of players — from independent record labels to major concert promoters — are drawing up plans to capitalize on fans’ appetites for everything from the latest club shows in Hollywood to decades-old film of the Grateful Dead in Copenhagen.”