Hi again -
hooray for walking and winnie the pooh!
If you find a music class, let us know how it goes. I also had some more ideas for you:
If you can't find it, build it. Maybe you can locate some other moms who have little ones at your ds' level and form your own music/movement/story time. share the joy.
Also, If you can find some interested older kids (age 7 to 11 maybe) to interact with your ds. This can be formal (as in hiring a mother's helper) or making friends with an older child in the right setting. (sunday school or equiv., library, book store, etc.).
When my son was a very young tddler occasionally we'd run into an older child at a book store or library who was practicing reading out loud and enjoyed reading to younger kids.
This would be a stretch but maybe you could join an all ages home schooling grop for their park days or other activities (in the Spring?)
last idea: local high school or college with an early childhood education program where their might be some students interested in precocious baby development. Maybe one of these young people would be interested in playing with your ds. kinda strange sounding but could work with the right person. Along those lines, adopt-a-grandparent...
back to the library storytime dilemma. children's bookstores often host storytimes that might be a better fit than your library's.
Good luck!