DEFINITIONS OF CLASSICAL FORMS FOR THE SAKE OF THIS COMPETITION
I will make this as clear as possible.
When I write ABAC or something like this, the letters represent a musical section usually an even number of measures long. So if you write an 8 measure A section, and the form goes AAAB, you would repeat that exact phrase 3 times, followed by a contrasting one.
Keep in mind that the musical examples are works of masters and may be more complex than the exact form indicates.
I posted earlier:
Alright, people. The suggestions so far have been ragtime, waltz (in a classical sense), minuet or scherzo, sonata, rondo, theme and variation (passacaglias would fall under this category). I would also like to suggest the fugue, invention, canon. I think these are all valid.
This is a looser form, almost through composed. We'll follow this link and say a ragtime should be written AABBACC, AABBCCDD or AABBCCA. We'll throw AABBACCDD in as well since the famous Maple Leaf Rag follows this form. The first B section starts at 0:42, the third A section starts at 1:17, the first C section starts at 1:35 and the first D section starts at 2:12.
MJTTOMB is right, there is no standard form for a waltz, partly because there are so many types of waltzes. A waltz can be just about anything in a triple meter (3/4, 3/8 usually) with a strong first beat and weak second and third beats. Think oom-pa-pa. Chopin's Minute Waltz (Valse au petit chien) has always been one of my favorites, but a simpler one would be Waltz in B Minor by Schubert. I'm a little hesitant to allow this style of piece due to lack of form, but there was a lot of interest so it's all good.
We'll go with minuet form or rounded binary or ternary form. MJTTOMB had a good example of this in his post. Let's keep this in triple meter as well, with the ABA' (the A' is a variation of the A section) of rounded binary, or the ABA of ternary form. Two additional examples of this would be Beethoven's or Bach's Minuet in G.
Look at MJTTOMB's definition. It's spot on. Basically three parts: exposition (2 or three themes that may or may not repeat) development (a section that creatively warps the three themes and plays around with using the themes to make new material) and the recapitulation (a restatement of the original themes, though not usually exactly in their original forms, and a conclusion).
A rondo form is basically ABACA, ABACADA, ABACADAEA, etc. Basically an evolving piece comprised of varying sections, with an original theme before and after all of the varying sections. There are tons of these pieces. The Für Elise (cool video huh?) is one of a huge number of rondos. The first theme is repeated and ends at 1:03, then comes back in at 1:30, and ends at 2:00, then comes in for a final time at 2:33, with B and C sections in between.
THEME AND VARIATIONS/PASSACAGLIA:
A theme and variations is exactly what it sounds like. You start with a theme and write a number of variations on that theme for the rest of the piece. For the purpose of this contest lets say at least 3 variations, and the theme and variations should all be of a decent length. I'll leave that up to you. Also, keep all sections close to the same duration. If I were a real stickler I would say they all should be the same length, but if you keep them close we should be fine. I love this piece by Vaughn Williams, and the start and finish of the variations should be fairly obvious. A passacaglia is basically a theme and variations with a repeating bassline underneath the entire piece.
This should not be attempted by the n00bcakes of the competition, but if you write a successful fugue I will give you mad props and probably bonus points. I am not going to explain the entire thing to you, but the wiki page isn't too terrible. If you write a fugue according to Bach's rules I will acknowledge you as a schnazzy person. If you write a 3,4 or 5 voice imitative motet in the style of Palestrina (not really a fugue, but close) I will most likely bow down before you. I've written a couple before and they are incredibly difficult.
I am going to be quite picky about this one. But I'll also give you props if you do it well. We will follow a 2 part invention in the style of Bach with these guidelines. I would refer to Bach's Invention No. 2 in C Minor. It's awesome. I will not explain the whole form as I will run out of characters, but if you look it up, keep strictly to the guidelines.
A canon would be a piece there is only one melodic line. This melodic line is written in such a way that you can start playing that melodic line from the beginning while the existing line is already playing to form a sort of counterpoint. Row, row, row your boat is a good example (I'm not linking you on that one.) If you want to write variations of canons, check out the wiki.
Alright, that's it. You're welcome to post more forms if you'd like that I could approve, but I think these will be the only official ones once the contest starts. I know these seem strict, but they really aren't, which you will realize as you are writing. Also, there is room for creativity, just let me know before you get totally out of hand.
No fantasias, nocturnes, or anything strictly through-composed!
I love you guys.