What's the song that plays?

On alot of cartoons and stuff, there is a little song that plays if they're on a ranch or in 'the old west' or something like that. Its a simple little blues riff on an acoustic guitar. I've already figured out how to play it, i just dont know if its an actual song thats been recorded by a major artist or anything...this has been driving me crazy all day, please help! :)