I've heard some tunes in recent years that were pretty close to that same idea. The idea was you turn on the radio and you want to hear some music and up comes a commercial.
The idea was I'd never amount to anything in music, The theme there was that I was talented, but I wouldn't work hard enough to do anything with it.
I start out with words, with the idea, the line. Then after I get a line or two, I try to find what melodic line those lines would be suited to. As soon as I find the form I can finish the song in my head.
I'm always storing away phrases and ideas and things that I think might turn into songs.
I have no idea what I'm doin'. I've never seen me.