Screenshot of p. 2 of YouTube's "Most Subscribed Musicians -- All Time" page.
The "lisalavie1" channel is 34th Most Subscribed Musician on YouTube (March 1, 2010)
P. 1 (not shown) has Musicians 1 through 24, while p. 2 (shown above) has Musicians 25-48.

Less than half of the fifty most subscribed musician channels were run by independent or unsigned musicians.
Most of the fifty most subscribed musician channels were run by music labels, or by musicians who are signed to major labels.