One more thing needs to be added to this discussion: any "song" which does not include the melody is not copyrightable in the US. In fact, I can go right now a print out the chords to "As Time Goes By", with the song title printed boldly at the top, and sell them a dime a copy with no legal restrictions at all. Many websites offer such. So what's the big deal about styles or even midi files and copyrights? To my knowledge, if it doesn't include the melody it's mine and yours and everyone's to use freely. Not so?