B.
I am a working mother too, and I have had a hard time finding after-work activities. But I have found 2 great nighttime music programs:
The BEST music program I have my daughter in (2yr old) is MacPhail School of Music. They have programs in St Paul at the Temple on Grand & Syndicate -- but not during the summer. Right now they have a tues or thurs night program for the summer at 6:15pm downtown mpls. Perfect for a working mom! It is an hour long class of singing and crafts and musical exploration. The teacher is a real muscian who plays guitar, piano, and has an excellent voice. High quality instruments are available for the child to explore with each class. Their program has a different concepts of music as a focus each class (loud/soft, accents, etc)
See http://macphail.org/program_studentsyoung_childhood_arts.htm
The 2nd recommendation is Kindermusik. Its on summer break right now (I think) but classes meet at the Hillcrest Library / Rec Center on tuesday nights. The class is short at 30 mins, but my daughter loves it anyway. Contact Amy Weier (the Kindermusik instructor) at ____@____.com for more info. This is less academically musical, and just focuses on singing and dancing and making noise with kindermusik branded instruments.
Both are parent-child classes.