People have definitely worked the music metaphor before, but they tend to go with historical figures, books, and movies more often than musical compositions. So quick answer: no, what you reference here isn't especially cliched or overused. Whether the "ups and downs of life" part gets a little melodramatic will ultimately come down to execution. And while I like the idea of attacking it from a music theory angle, there's something strangely noble sounding to me about the fact that you've been perfecting this for the last several years out of sheer passion. It might be a nice thing to reference in passing.