One day after iTunes upped the prices for some of its DRM-free digital downloads to $1.29, Amazon and Wal-Mart have also increased their prices.

That was fast.

One day after iTunes upped the price for some of its DRM-free digital downloads to $1.29, Amazon.com and Wal-Mart have also increased their prices to $1.29 and $1.24, respectively.

Of the top 100 MP3 downloads currently listed on Amazon.com, eight of them are now priced at $1.29, up from 99 cents. Those include selections from Jamie Foxx, Beyonce, Britney Spears, Kings of Leon, Brad Paisley, Journey, and The Fray.

Other Amazon tracks are available for 79 cents and 89 cents.

"As with any product on Amazon.com, product pricing is subject to change," an Amazon spokeswoman said in an e-mail. "At Amazon.com we are continually working to bring value to our customers, through low pricing, selection, and convenience."

On Wal-Mart's MP3 store, 17 of the top 100 are now priced at $1.24. They also include songs from Britney Spears, Beyonce, Brad Paisley, and Jamie Foxx, as well as Kelly Clarkson, Pink, Carrie Underwood, and Leona Lewis.

Wal-Mart previously priced most of its songs at 94 cents, but there are now selections available at 64 cents.

Apple on Tuesday started selling tracks without copyright protection, or digital rights management (DRM). They also introduced tiered pricing  99 cents for standard tracks, $1.29 for premium, popular songs, and 69 cents for older, less popular songs.

Amazon and Wal-Mart made no obvious mention of the price hikes on their Web sites.

Editor's Note: This story was updated at 3 p.m. Eastern time with comments from Amazon.