Apple’s iTunes Music Store continues to dominate the digital music market, according to new data released today by The NPD Group. Echoing the same number Apple touts publicly, the research firm said nearly 70 percent of music files downloaded legally between December 2003 and July 2004 were downloaded from iTunes. Napster’s share for the same period was 11 percent, while MusicMatch, RealNetworks and Wal-Mart each reached a six percent share.