Van der Zwaan Dance Studio
Zwaandance on Shattuck is amazing! My daughter and many of her friends have been taking classes there for years. They also offer hip-hop classes. The teachers are truly amazing!
My daughter started taking ballet at 10 or 11 at Van der Zwaan Dance Studio in north Berkeley (Shattuck and Cedar). The classes indicate the age range, and although she's usually been among the oldest in her classes, there's always been at least one or two students her age. She's made steady progress, and she's still taking classes there as a 14-year-old. http://www.zwaandance.com/
There are lots of classes for 4/5 year olds at Van der Zwann dance studio on Shattuck between Vine and Cedar. Very nice studio!