A future post will provide more information about Bach to Baby and the baby-friendly sessions at the Royal Opera House.
Slightly closer to home is Poem Parties on the St Johns Wood/Hampstead/Maida Vale border - they run classes as well as being a children's party venue. More information can be found on our things to do page.
Similarly on the Swiss Cottage/St Johns Wood border is Huggle (also on our things to do page), where there are lots of classes too.
As you can see, the areas surrounding Marylebone are quite saturated with classes. Hopefully we should see more classes and activities coming to our area soon. Until then, a bus or tube ride from can get you to some classes.