Its a march ... written in November
Its all about orchestration: combining different instruments so as to make the result sound more attractive
Sustained seconds and fourths are lovely multipurpose chords
The notes on each individual guitar string were assigned to trumpets, trombones and tubas and theres a bit of variation too: a piccolo is used later on in the song
And lo and behold it completely changes the feel. Makes it a different song.
Incidentally it proves the point that the guitar is an instrument of harmony (as is the piano). It must be ten times more difficult writing music if youre a tuba player cos you can only play one note at a time (... or is it? ... any tuba players out there writing toons?)
One of the things you need to do when you orchestrate is to check is whether the notes you write for an instrument can physically be played by that instrument. Luckily I have Dave Stewarts excellent books on songwriting which inspired me to check whether a tuba really can play a low low E. It cant. But it can play a really really low F. Phew