is there a standard or some common structures for a choral SATB piece? (sonata form, rondo form, these kinds of things) I wrote a very very short choral work and want to expand on it but not sure what form I should use.

From my experience with choral- it's not so much the form of the piece but more so the voice leading in each of the parts. The rules for writing choral parts are followed more closely than the rules for writing instrumental parts. One of the reasons why is some intervals are harder to sing than they are to play on an instrument.

I'd look up the standard part writing rules from any freshman theory textbook.

It's been a long time but some big ones that pop out in my mind are:

No parrallel octaves of fifths. (With modern music, this became more accepted, but extended use is still generally avoided in choral music)

Avoid consistent voice part crossing. This is where you'd have the bass part singing higher than the tenor part. It will happen occasionally in some pieces (even Bach's) but any well written choral piece will avoid over using it.

Strange intervals. As mentioned above- some intervals are harder for the human voice to sing. It's not impossible, but it will just the piece that much harder to learn and awkward. Always try and look for a solution where the parts all lead from one note to the next smoothly. Movement by seconds and thirds is okay, but stay away from tri-tones and try not to have consecutive leaps by the 6ths or larger. :)

The only exception to this is the bass part- which will commonly have large skips in the part. Even so, they keep the intervals mainly to the root of the chord and as logical as possible.

Chord tone doubling: This refers to the rules involved with what chord tones you should double. While this rule is easy to break, it came out after years of writing choral music and realizing what chordal build up sounded the best and what sounded the weakest. This also deals with texture. If you have a low part of the song- you don't want all the voices singing close intervals in that lower range. It will get way too muddy.

J.S. Bach is the go to man to learn how to write really, really solid choral pieces. He is who every freshman music major studies for voice writing.

I've tried to give you a very brief overview- but your best bet is to get your hands on a text book that shows you examples. You might be able to find one for cheap used somewhere.

Hope that helps!

Here's a few Baroque forms I remember, and I think all of them can used for choral OR instrumental arrangement:

Canon, Fugue, Chaconne, Passacaglia

Here's a great online music dictionary that has these terms defined, along with just about any other music term you can imagine.

http://www.music.vt.edu/musicdictionary/

Hope this helps,
Brian

thanks guys. Actually I have a decent amount of theory under my belt and am familiar with counterpoint (all those rules you mentioned) but just wasn't sure how to order my sections. I will check out those terms and most likely try and follow one of them. Thanks for the time guys. If anyone else has other forms the more the merrier.