First movement of Symphony in F.
For those who know about this sort of thing, it's not a properly written piece as the different sections aren't formally introduced and there aren't as many repeats as there should be, but I didn't want to leave my adoring public feeling bored.
There are four main sections to the piece:
The opening trumpet (yes, that is supposed to sound like a trumpet) fanfare bringing in the string section bit by bit with a descending twiddle on the oboe and flute (not a full orchestra I know, but the speakers started crackling if I added any more instruments and the timpani sounds even worse than the trumpet). The section finishes on an E flat major chord but a strong major seventh sounding through on the second violins gives a very discordant end to the section.
This leads to the second section based around a Bbm chord sequence in the strings supporting the mellow tune played by the oboe.
This breaks into a more spritely Bb major section with the oboe and flute taking the tune and its harmony while the string section and finally the trumpets gradually come in with their own little additions to the repeated 4 chord sequence Bb, Dm, Eb, F. There is a brief, quiet, foray into the F, Cm, Eb7 sequence of the beginning section, before returning for a final blast of the 4 chord run. The piece then returns to the fanfarish feel of the opening before the strings return alone to the Bbm chord sequence and finish on a long F chord.
This chord brings us to the final section of the piece starting with the oboe and flute defining the simple F, Bb, C, F chord sequence gradually taken up by the trumpet and then each string instrument. The piece ends with the upper and lower string parts taking it in turn to give a new feel to the piece by bringing in some more complicated rhythms than previously encountered.

Anyone who didn't find that pretentious enough needs their head examined.