Yahoo Groups where musicians can promote their music: *
http://groups.yahoo.com/group/unsignedbands2/
http://groups.yahoo.com/group/unsignedbandsglobal/
http://groups.yahoo.com/group/Multimedia-Madness/
http://groups.yahoo.com/group/all_unsigned_artists/
http://groups.yahoo.com/group/AspiringUnsignedMusicArtists/
http://groups.yahoo.com/group/DiggingUpTheBestUndergroundMusic/
http://groups.yahoo.com/group/DreamsOfMusic/
http://groups.yahoo.com/group/garagebands2/
http://groups.yahoo.com/group/getnoticedtoday/
http://groups.yahoo.com/group/getpublicity/
http://groups.yahoo.com/group/groupsandsingerswanted/
http://groups.yahoo.com/group/ilikemusicunsigned/
http://groups.yahoo.com/group/independentartists/
http://groups.yahoo.com/group/independentmusicians/
http://groups.yahoo.com/group/indie-music/
http://groups.yahoo.com/group/indierockbands/
http://groups.yahoo.com/group/localandunsignedbands/
http://groups.yahoo.com/group/LocalBandSupport/
http://groups.yahoo.com/group/lookhereforunsignedbands/
http://groups.yahoo.com/group/Mega_Unsigned_Bands/
http://groups.yahoo.com/group/Music-Classifieds/
http://groups.yahoo.com/group/Musicians_Spotlight/
http://groups.yahoo.com/group/musicianswantedworldwide/
http://groups.yahoo.com/group/musicnetbusiness/
http://groups.yahoo.com/group/musicpromotion/
http://groups.yahoo.com/group/musicthoughts/
http://groups.yahoo.com/group/NewMusicians/
http://groups.yahoo.com/group/originalmusic2/
http://groups.yahoo.com/group/PROMOTE_YOUR_BAND/
http://groups.yahoo.com/group/promote_your_music/
http://groups.yahoo.com/group/PROMOTEyourBAND/
http://groups.yahoo.com/group/PROMOTE-YOUR-BAND/
http://groups.yahoo.com/group/promote-your-music/
http://groups.yahoo.com/group/reachingforthestars/
http://groups.yahoo.com/group/rockinunsignedbandspit/
http://groups.yahoo.com/group/Serious-Musicians/
http://groups.yahoo.com/group/singerandgroupswanted/
http://groups.yahoo.com/group/singersandmusicianshangout/
http://groups.yahoo.com/group/Singers-Musicians/
http://groups.yahoo.com/group/songwritersandpoets/
http://groups.yahoo.com/group/songwritersdiscoveryzone/
http://groups.yahoo.com/group/songwriterswanted/
http://groups.yahoo.com/group/stars_of_the_future_promo/
http://groups.yahoo.com/group/truemusicfansclub/
http://groups.yahoo.com/group/unregistered/
http://groups.yahoo.com/group/unsigned_artists_n_groups/
http://groups.yahoo.com/group/unsigned_artists_standing_2gether/
http://groups.yahoo.com/group/unsigned_artists_USA/
http://groups.yahoo.com/group/Unsigned_Bands/
http://groups.yahoo.com/group/unsigned_butwanted/
http://groups.yahoo.com/group/Unsigned_Musicians/
http://groups.yahoo.com/group/UnsignedArtists/
http://groups.yahoo.com/group/unsigned-artists/
http://groups.yahoo.com/group/Unsigned-Aspiring-Artists/
http://groups.yahoo.com/group/unsigned-bands/
http://groups.yahoo.com/group/unsignedbandsgopublic/
http://groups.yahoo.com/group/unsignedbandsinternational/
http://groups.yahoo.com/group/unsignedbandz/
http://groups.yahoo.com/group/unsignedhardrockbands/
http://groups.yahoo.com/group/unsignedmusicians/
http://groups.yahoo.com/group/Unsigned-Solo-Artist/
http://groups.yahoo.com/group/up-comingbands/
http://groups.yahoo.com/group/USBPsex/
http://groups.yahoo.com/group/web_music_newswire/
http://groups.yahoo.com/group/youngmusicianslounge/
http://groups.yahoo.com/group/youngrockandpopmusicians/

* Note: Groups have different policies about posting promotional messages, so please check with the owners of each group before posting.