calendar of may events       All listings are accurate at press. Please call ahead to confirm events. Listings are arranged alphabetical by community. A Adult C Child Y Youth M Member NM Non-Member PP Per Person Thursday, 1 Big Apple Circus. More ... Free Museum Admission       Gas (and basically everything else) is increasing in price, so each month Bay State Parent magazine compiles a list of Massachusetts museums that offer free admission for kids and/or families, so you can spend quality time with your children without emptying your wallet. More ... EDITORS' PICKS MAY FAIR, SWAN BOATS, ARTHUR'S BIRTHDAY, & 2ND ANNUAL PARK SERVE DAY Month of May Offers a Range of Activities for Families BY susan scully petroni & carrie wattu       1. Sunday, May 4: Make plans to spend the afternoon in Harvard Square in Cambridge at the 25th Annual MayFair. The popular event takes place from noon to 6 p.m. and features six stages of live entertainment, 30-plus restaurant vendors, and more. But what families will love is Chalk on the Walk ... More ... Story Hours       Editor's note: Story hours are free, unless noted. They are listed alphabetically by location of the story hour. Drop-in Storytime. Memorial Library, Acton. Fridays, 10:30 - 11:15 a.m. 978-264-9641. www.actonmemoriallibrary.org. More ... Mother's Day To-Do List BY carrie wattu       Moms, after sleeping in, waking to a clean house, and enjoying breakfast in bed, why not have some family fun time at one of the following Mother's Day events (and your house will stay clean … for the afternoon at least). More ... Mom only events, support groups, play groups & More       Note: Groups and classes are subject to change, please confirm before attending. Drop-In Playgroups. Isis Maternity Locations in Arlington, Brookline, and Needham. Groups for non-mobile babies (0-1 year) and for mobile babies up to 3 years. Enjoy a comfortable space with ageappropriate to... More ... Theatre and Musical Performances       Cinderella, Girl Authority Goes Broadway, and Mother's Day Family Concert. The Regent Theatre, 7 Medford St., Arlington. Sat., May 3: Makeshift Theatre Co's Cinderella, 10:30 a.m. A$10, C$8. Fri., May 9: Girl Authority, 7 p.m. Sing along to favorite show tunes including Wicked, High School Mu... More ... Please e-mail your September listings and photos to calendar@baystateparent.com by Thursday, August 7th at 6 p.m. The deadline for October calendar listings is Monday, Sept. 9th at 6 p.m. For bonus calendar listings that missed our print edition, please visit the magazine's BLOG at http://baystateparent.blogspot.com/ and click on "bonus calendar listings link," found on the right side of the page.