AMP – online marketing service for Music Industry
Crogall – online music store for small bands/labels to connect with their fans
Abaltat – compose royalty free music
BalconyTV is a leading daily online viral music show that features bands, musicians and other variety acts on balconies around the world.
dbTwang – a social network for people who love guitars!
Echodio – platform for syncing, protecting and sharing your digital media collection. (Y Combinator Alumni)
Rocudo – online music community in which Fans discover and remix music in an innovative interactive format
DownloadMusic.ie – Independent Irish Music Chart – Pay for music by text
Muzu – Watch, Create and Share Music video playlists
Tapadoo – Firepit – creating apps for bands on tour.
Sonic Academy – learn to make music online.
Trezur – they make apps that “turbo-charge” your digital music collection
Grab Radio is here to revolutionise the way you listen to radio on your iPhone.
diddlyi – social network around Irish Dancing & Music Community
Any more that can be added to the list ?