This is an interesting article about the ways in which music theory - the guiding principles that provide a framework for how music is structured and written - is evolving in the world of pop/rock. The traditional I-V-I (Tonic-Dominant-Tonic) is giving way to other forms, as evidenced by a database that analyzed the chord structure of the top 20 songs from Billboard from 1950 - 2000.
It's interesting that the numbers do bear out that there is an evolution going on in music. But I have to wonder, how many of the song-writers made a conscious decsion to abandon established convention and deliberately write something that at the time was unconventional, and how many of these song-writers were getting by with a limited set of skills and knowledge, and they just got lucky with a musical hook, or melody, or something else?
I've always subscribed to the idea that it's better to be a well-rounded musician and have a multitude of experiences from which to draw performance. From "classical" music - and everything that catch-all word entails - to jazz and popular styles, band, orchestra, chamber, etc we are better musicians by playing a wide variety of music.
When I was an intern at the Pittsburgh Symphony in the early 1990's I worked with the Resident Conductor, Kirk Muspratt. I was studying Haydn Symphony no. 100 (the "Military" symphony) to conduct with a local community orchestra and he would ask me how/why I decided on cetain tempi, phrasing, dynamics, etc. After a while of giving answers that were variations on "because it felt right and I like it", I finally asked him what other ways there were to prepare a score for performance. He said to conduct Haydn Symphony 100 I first had to start with his early string quartets, then progress to studying the early symphonies, and finally his later works. I also needed to know his history, what experiences he had that may have made an impression on him and influenced his compositions, what were the circumstances surrounding the commissioning of the work, and what was "performance practice" at the time. Having all of that was the difference between giving a utilitarian and functional performace vs. an informed and inspired performance.
Classical music is called classical in part because it holds up over time. Trained composers and song-writers break with convention all the time, but they know what the rules are, and when they break them they do so in an informed and thoughtful way.
Remember, there are a lot of talented and creative people in the world with potential. But there are fewer who develop that potential.