The move is only the latest in the digital music space by Amazon, who remains a distant second to Apple in terms of sales. iTunes commands about 70 percent of the market , while Amazon controls just 10 percent. Digital music on the cheap may be one of the few ways the retailer may have left to compete.

It's not clear as to whether the price drop was a blessing from the music labels, or if Amazon has decided to take a profit hit in the name of gaining market share. It's no secret that some music industry execs would like to limit iTunes' clout in digital music, and may have given more favorable terms to competitors.

Walmart still holds the top spot for cheapest MP3s, though: of $0.64, $0.94, and $1.24 tracks, although popular tracks are typically priced at the highest tier.

Amazon , which allows customers to store music purchased through Amazon for free, in late March. As you may have guessed, this didn't go over too well with the music industry, who cried foul .

Apple raised prices on some of its catalog from $0.99 to $1.29 back in 2007 when it announced in May of that year. That price differential didn't last long however, and amid increasing competition Apple for DRM-less music in October.