Billboard is reporting that Amazon MP3's deals with record labels to offer certain albums a day early and a few bucks cheaper have caused iTunes to raise a few eyebrows... and flex some not-so-subtle music muscle.

In exchange for a Daily Deal promotion on a new album, Amazon has been asking labels to provide it with a one-day exclusive before street date and such digital marketing support as a banner ad on an artist's MySpace page and messages on label and artist Web sites and social network feeds.

"When that happened," the executive says, "iTunes said, 'Enough of that s--t.' "

As a result some labels have been opting out of the Amazon MP3 deal while others claim the situation is fluid and they'll opt in and out depending on the album and the amount of exposure iTunes is likely to give them. One major label exec who remains nameless, however, shot back:

"[iTunes is] . . . diverting their energy from 'let's make this machine better' to 'let's protect what we got.' "

The battle is over the initial, high volume sales when a new album hits the streets. If Amazon can dash in and scoop iTunes, they stand to syphon off a lot of the sales, and iTunes doesn't want to stand for that. Of course, the record labels could just give everyone the albums early and for less... We'd be just fine with that!

This, of course, is particularly interesting in light of the similar Apple vs. Amazon battles we've been seeing over eBooks pricing, where Amazon and not Apple is the entrenched market leader and Apple's iBooks the scrappy new comer. Can they fight -- and win -- wars on so many fronts?