Even as the recording industry staggers through another year of declining sales over all, there are new signs that a democratization of music made possible by the Internet is shifting the industry's balance of power.

Exploiting online message boards, music blogs and social networks, independent music companies are making big advances at the expense of the four global music conglomerates, whose established business model of blockbuster hits promoted through radio airplay now looks increasingly outdated.

CD and digital album sales so far this year are down 8 percent compared with the same period a year ago, according to Nielsen SoundScan data. And while sales of digital tracks through services like iTunes have risen 150 percent, to well over 320 million songs this year, that rise is not enough to offset the plunge in album sales. Overall sales are down less than 5 percent if the digital singles are bundled into units of 10 and counted as albums, according to estimates by Billboard magazine.

Still, despite the slide, dozens of independent labels are faring well with steady-selling releases by, among others, the Miami rapper Pitbull and the indie bands Hawthorne Heights, Bright Eyes, Interpol and the Arcade Fire. Independent labels account for more than 18 percent of album sales this year -- their biggest share of the market in at least five years, according to Nielsen SoundScan data. (If several big independent companies whose music is marketed by the major music labels distribution units are included, the figure exceeds 27 percent.)