Dance musician Michael Shapiro recently asked me a question about the music for squares: He said some callers tell him that the music for squares doesn't have to be "square" (32-bars, AABB), and wondered how this could be.
It depends on the style of square dance.
A New England square is basically a contra in a square formation: It fits perfectly in an AABB pattern, with the prompts happening on the 7&8 (or perhaps the 5,6,7&8) of the previous phrase. The break figure is also choreographed to fit an AABB pattern exactly. So for this, a square tune would be absolutely required.
A Southern square, on the other hand, is called in 4- or 8-beat (2- or 4- bar) phrases rather than thinking about the 16-beat (8-bar) phrase (the entire A or B). So while it could use a "square" tune, it can also use tunes with AABBCC or AABBC structures, or a tune in which one part has an extra beat.
The calling is connected to the beat, but the phrasing of the dance and the phrasing of the tune aren't necessarily tied together. The choreography is a bit more fluid, so a swing could be eight beats one time, 12 or 16 at another time in the dance, while certain other moves (chains, right-and-left-thru) would typically start only at the top of a phrase. Good callers use this fluidity to improvise, adding or removing figures. (Of course, they must know what the dancers are capable of, a skill that takes experience to master).
By the way, this is why Southern and Western squares can have swings that start at the top of a phrase and end in the middle of a 8-bar (16-beat) phrase -- because the dancers aren't hearing that longer phrase, but rather the 8-beat phrase.
A Western (patter) square can follow the phrasing tightly, as in New England squares, or loosely, as in a Southern square. The difference between patter and Southern (besides the accent) is that in Southern squares the caller actually "follows" the dancers in a sense, watching until they are about two steps from finishing a move before beginning the next call.
It is possible to have a New England-style square that is choreographed for AABBCC, with a short (BB) break so as to stay on the same music for the same actions throughout the figure, or with an AABB break and not worry about ending on the B2 (but still sticking with 8-bar (16-beat) phrasing.
Choreography for Southern and patter squares can be AABB, or AABBCC, or AABBCDE, or some other mess that the caller would prefer not to explain to the musicians or dancers. The break in such a dance might be shorter, or not. The trick would then be ending with the music, or just having the dancers promenade until the band finds a place to go out. (For the caller, ending a square is an art unto itself, because he/she must signal to the band while still calling to the dancers).
A singing square, of course, is as tightly choreographed in its own way as a New England square but requiring a specific tune in a specific key.
Square calling is also dependent on the musicians' style. The Missouri Old Time music of guys like Chirps Smith, Jim Nelson and Geoff Seitz is very conducive to Southern or patter squares because the beat is more predominant than the phrase or the tune. The question "are we in the A or B?" doesn't really matter. Musicians playing New England or French Canadian-style tunes would be more conducive to New England squares.
Callers need to understand what they are asking for, particularly if it's not their "home" style. When I left Louisville, I had to learn anew how to listen to the band because a different style predominates in this area. This affected my contra calling, and also taught me to prepare certain types of squares for certain types of bands.
It would be expecting a lot for callers to understand the intricacies of every musical style as they relate to square-dance calling, and I'm certainly not as expert a square-dance caller as I hope to become. When I think of contra callers who are true masters at calling squares, I think of Tom Hinds, Kathy Anderson, Carol Ormand, Ron Buchanan, Bob Dalsemer, maybe David Kirchner.
A note about choreographic differences:
Southern squares -- think visiting couple squares (first couple swing, first couple lead right and do something with couple two, then lead on to couple three, etc.) (Meanwhile the inactive couples get to either watch or flirt or be creative/spread meyhem).
New England -- big focus on Heads vs. Sides choreography (heads do this, now this, now this, now everyone find your corner...)
Western -- focus on everybody active. Although there is Heads/Sides choreography here as well, the inactives won't stand there for more than one or two moves.
Michael also asked about crooked tunes with extra beats or bars, say sections of 8,8,10,10 instead of 8,8,8,8 bars.
This is trickier for sure, but I suppose a caller who knew the tune could add extra balances or something in those places. Most of my notes above are about extra sections (AABBC, AABBCC) rather than extra measures. Extra sections are not really a problem when calling Southern- or Western-style dances, IF you know the band will be playing a tune with extra sections.
I hope other experienced (and beginning) square callers will weigh in here -- maybe tell what sorts of music you prefer and what styles of squares you prefer to call and dance to, and why.