Dot-coms are flocking to affiliate with Universal Music Group in the days after announcing it would start testing bluematter, a new digital music format. So far Music.com, EMusic’s RollingStone.com, RioPort, Launch.com and Lycos Music have teamed with UMG in the bluematter trials. Besides audio files, bluematter gives Netizens song lyrics and credits as well as photos and bios of artists.