I saw that question on a Captain Beefheart record sleeve (okay, on the back of a CD) once upon a time. I don't know what it's all about, but I wish I did know. About the Booga-Wooga music.
So, Mr. Joss Pip-Knight "Shuggie" Otis has taken my suggestion of listening to the Paris Symphonies--including, as I said, my favorite, No. 87, which I'm nicknaming "The Eel." Which is what Joss nicknamed it. But the thing is, if you don't know the details of their form, Classical era symphonies tend toward a wallpapery, patterny sameness that will do nothing to help you forget all the times you've heard similar music in restaurant bathrooms.
Thus, in his honor, I present everything I know about the form of the Classical era symphony. This won't take long.
They ALL have Four Movements: the first is for the head, the second for the heart, the third for the body to dance to, and the fourth is ROCK 'N' ROLL.
Movement One presents two themes (a theme here means a tune, and in Haydn they're pretty short, maybe 16-20 beats . . . maybe that's totally wrong); sometimes one theme is masculine and one is feminine, but if not they do contrast in some way--though it's often pretty subtle. Don't forget to listen for changing orchestration, that is, the mix of instruments playing at any given time. Each theme will be presented in turn, then the presentation is repeated (although the repeat is often skipped). Then they FIGHT.
By the end, the female theme has usually been taken over to the key of the male theme. I'm just saying.
Movement one might begin with a French Overture, so if the beginning sounds pompous and ponderous and slow, and goes Ba-Buuuuuhhhhm, Ba-Buuuuuhhhhm, that's a French Overture.
Movement Two is a love song, and usually slow. It might be in rondo form were a whole section of music will be repeated after variation sections, again and again. That's the wallpaper-pattern I mentioned.
Movement Three is a dance in waltz time, or three beats per bar. Actually it's three dances: dance A is played twice, then dance B, which might be a minuet-and-trio, which means only three instruments are featured, so listen for the stripped down orchestration. Then dance A is played again, only a little different this time. This is really where you hear the wallpaper.
Movement Four is ROCK 'N' ROLL. Just pump your fist in the air. Pump it like you just don't care. It might be in rondo form too, or in the form of movement one, which is called sonata-allegro form, though that's not common in the Classical era, I don't think. All Classical era symphonies end the same way. You'll know it when you hear it. It didn't bother anybody--this is weird, but originality was not an aesthetic virtue in those days.