Apple continues to dominate the retail music market in the United States. The multinational corporation held off retail giant Wal-Mart and defended its top spot on the list in the first six months of the fiscal year 2008.

The results, which were provided by NPD Group in a report, show that Apple Inc managed to top the list of the retail music market for the second straight period. The Cupertino, California-based company moved into the lead this year to become the first online service ever to claim the top overall retail spot.

According to the NPD Group study, Apple will consolidate its lead in the retail music market on slowing CD sales, said NPD entertainment industry analyst Ross Crupnick. Moreover, NPD also said in its report that Amazon’s future looks bright, especially after the company launched its own DRM-free music store.

"Amazon's CD buyers tend to be older, so they haven't abandoned the CD format to the extent seen in the average music buyer," explained Crupnick.

In another report released in April, Crupnick said that Amazon's MP3 service success hasn’t hurt Apple iTunes sales. The fact can be explained through the different demographics the two services magnetize.

The third spot on NPD’s list was clinched by Best Buy, followed by Amazon and Target. Ten years ago, Apple wasn’t even in the top 10 largest retailers of music.