Download MP3 via SMS straight to iTunes?

Hi there,

Hope someone here can point me in the right direction.

I'm searching for an SMS based music download service to use for music promotion.

Specifically, one where a user texts a simple word or number and then a free mp3 is instantly downloaded to their iTunes, or whatever their music player is.

I've seen many services where you can pay for music using SMS and are charged to your phone bill, or services where there are multiple steps involved (lots of numbers, Pins, codes, etc) , or ones where the user needs an app or an account .... I'm looking for something super simple and direct.

Any help is greatly appreciated!