This was a very comprehensive article on song structure. Nicely written. And unless I missed this somewhere on the page, if there is room to expand upon this article I would add an explanation of a "Breakdown section," which does differ from a Bridge or Instrumental Interlude in that instruments will tend to not only get quieter and play more sparsely, but some will usually drop out completely, and in live renditions it is sometimes the part of the song in which the singer talks to the audience. Great article though. Kevin Thomas