Kids at the Reebok Sports Club/NY.   (Photo: Yencey Campana/courtesy of Millennium Partners Sports Club Mgmt LLC)

Type-A parents have their tots’ autumn agendas already locked down, but for the rest of us zhlubs early September is a glorious time: open-house season! Nearly every music center, kids’ club, and arts-and-crafts mecca is likely to be offering free trial classes right now. Shop around. There are too many to mention, but here’s a few standouts worth considering.

WHAT: MiniMasters, 9/4
WHY GO: Normally anyone promising “Harvard prep for tots” makes this mom run the other way, but the copious offerings at this Tribeca membership-based “cultural learning center” consistently earn praise from pleased parents. Experience BabyMuscles, MiniSigners, Gym Rock, MiniBallet, Suzuki Violin, and more.

WHAT: City Treehouse, 9/8–9/12
WHY GO: With inexpensive membership and a relatively chill vibe, this brand-new Chelsea kids’ club offers eighteen different classes, including Karma Kids yoga and Bilingual Birdies in Spanish, French, or Hebrew. The swell tree-house-themed indoor play area with multitiered water table is perfect for rainy days.

WHAT: Brooklyn Arts Exchange, 9/6
WHY GO: Witness some of this Park Slope staple’s unusual dance classes: Hip Hop, Boys Movement, Tumbling, Physical Comedy, and more. Check out the play space, meet the teachers, quaff some free refreshments.

WHAT: Reebok Sports Club/NY, 9/3–9/6
The Sports Club/LA, 8/26–8/29
WHY GO: All gyms should have some sort of child care (Dear Crunch: Are you reading this!?). Lucky you if you’ve got one of these fancy ones in your hood; they offer (not inexpensive) “enrichment classes” for offspring 6 months to 5 years. These include Storybook Oven, Tots and Tutus, Princess Ballet, and even a preschool alternative (is this what overcrowding has brought us to?). Nonmembers’ kids are welcome, but that sort of defeats the parents’ purpose.

Mini­Masters: 9/4, 9:15 a.m. to 5 p.m. 100 Reade St., nr. W. Broadway (212-374-1747 or minimasters.com); free, RSVP required. Brooklyn Arts Exchange: 9/6, 10 a.m. to 5 p.m. 421 Fifth Ave., nr. 7th St. (718-832-0018 or bax.org); free. City Treehouse: 9/8–12, times vary. 129A W. 20th St., nr. Seventh Ave. (212-255-2050 or citytreehouse.com); free, RSVP required. Sports Clubs, Upper East Side: 8/25–29, times vary. 330 E. 61st St., nr. Second Ave. (212-355-5100, ext. 4253); free, RSVP required. Sports Clubs, Upper West Side: 9/3–6, times vary. 160 Columbus Ave., at 67th St. (212-501-1434 or e-mail jburt@reeboksportsclubny.com); free, RSVP required.