I agree that Music Together is perfect for an 11-month-old - at least in my experience. We actually never did it formally but I've been to a class here and there, and other music things with my kids, and I found that age to be the best suited to music classes.
With DD1 I began her in gymnastics at a "real" gymnastics place at almost 2yo. She took it for three years there and I loved it. I've never done the My Gym/Gymboree/Little Gym classes, and those sound really convenient for you (and the Gymboree does include music, as others have said), so it's probably best to just go with one of those, but I figured I'd just throw out another option.
As others have said, it completely depends on your child and you should try out each option to see what works best for you.
My son went to MyGym from about 6 months to 2.5 years and loved it. Especially once he started really walking and climbing, he just loved having a space where he could run wild and tumble all over. I'm sure the experience differs from place to place, but we loved our MyGym instructors and had such a great experience there. It was the perfect mixture of free play and structure for us. We tried Gymboree, but I didn't care for it. We also did a music class for a while, and while I loved it and thought it was adorable, my son was bored and just ended up running around and not paying attention each time we attended. Once you do some trial classes, I'm sure you'll know what's best for your child.
Bumping this up with a question...we have two of the same gyms within driving distance of our house. One is about twenty minutes further away than the other, but it's in a much nicer area. Has anybody noticed if the gyms vary from place to place or if they're pretty consistent across the board? I don't mind driving the extra twenty minutes once a week if it's a nicer gym. Of course, I can drive over and check them out, but I thought I'd ask here first.
"For this child I prayed; and the LORD hath given me my petition which I asked of him" 1 Samuel 1:27
Our answered prayer-12*24*2010
KK812-IME those types of places don't vary much one from the other, but the clientel will. I have found the places in nicer more affluent neighborhoods will have fuller classes, while the others might have less classes overall which are less full.
We did a kindermusik class in an affluent area and the moms were judgmental snobs and the kids were brats. I'm sure it was just the mix of people (most of the moms were friends), but it was an interesting experience to say the least. I think the most important thing is the personality of the instructors, might be worth doing a trial class at each place if you can.