Music has long been part of NPR’s identity, but perhaps never more than in recent years, as its NPR Music Web site has become an increasingly popular outlet for artists and music fans.

The site, at www.npr.org/music, features many artists who don’t get heavy airplay on commercial radio, from the soprano Renée Fleming to the jazz musician Fred Hersch. But big-name pop acts get attention too. This month the Web site streamed 45 shows from the Bonnaroo festival, including the sets by the Dave Matthews Band and Tori Amos. More than 40 can still be found on the Web site.

And on Wednesday NPR Music went mobile, introducing an iPhone application that provides a platform for the more than 300 pieces of new content  from videos to blog posts, podcasts to live concerts  that are added to the site each month.

“There are music magazines and places to hear music,” said Anya Grundmann, executive director of NPR Music, a 10-member crew based in Washington. “We’re trying to tap into all of the different ways to present music.”