Jean-Michel Veillon told me that with Breton music the best way to understand the different rhythms is to learn the dances. And despite the fact that I'm a terrible dancer, I agree with him. The music really makes much more sense when you understand the dance, and you'll eventually be able to listen to a tune and tell what kind of dance it is based on the internal rhythm. At most of the festou-noz I've been to in Brittany, the band doesn't even tell you what dance they're doing, they just launch into a tune and people can figure out what dance it is based on the rhythm.
And yes, the tunes you listed are types of dances.
There's a humorous but fairly useful introduction on youtube here (note that in the second segment they say "an dro and hanter dro" but only the an-dro is shown there, and many of these dances are not that common -- the avant-deux dances are kind of like our contradances here in the States, and there's one dance there that's very much like the Gay Gordons from Scotland; I've never actually seen them myself in Brittany, but most of my time there has been spent around Vannes and the Presqu'Ile de Rhuys; there are lots of different regional dances throughout Brittany):
http://www.youtube.com/watch?v=UUXSTxkq ... 0A&index=0
Here's a really nice an-dro, followed by a bal de rhuys, from a beautiful island in SW Brittany, Belle-Ile-en-Mer:
http://www.youtube.com/watch?v=eBsc1xtJVBo&NR=1
Watch the older dancers, they know what they're doing.
For more detail, there's a website that describes the different dances here, broken out by region:
http://dansal.gwalarn.org/pagedecadredansebretonne.html
For example, the an-dro and hanter-dro are from the southwest, around Vannes...here's the page for the hanter-dro:
http://dansal.gwalarn.org/hanterdro.html
Pretty much without exception, Breton dances start out on the left foot.
If you don't read French it'll be a bit difficult to get through all this, but at least you can see the basic rhythms of the dance outlined here. This site is also great because it provides the common variations on each dance: the "tricot" is a sort of combination of an-dro and hanter-dro (you switch from one to the other during the dance) and the "klam" is a form of hanter-dro where you drop to your knees periodically in the tune when the musicians yell out "Klam!"
Some of the dances like the gavotte and plin have a "bal" portion that is slower and in a different rhythm: you start with the "call," which is a slow warmup to get the dancers ready, and then you launch into the full-speed gavotte or plinn; after awhile you get to the bal and everyone is happy because they can slow down and catch their breath, but then you launch back into the gavotte or plinn.
You can see it here (minus the call at the beginning) with a gavotte:
http://www.youtube.com/watch?v=PH0CZrnj ... 0A&index=0
The bal begins around 1.45 into the video.
Note that most dancers conserve their energy and take small steps -- this is so you can dance all night long and not get exhausted!
And you did just fine playing those tunes, by the way, it sounded great!
