The thought of an “underground” party might conjure up images of a chic 1920s speakeasy or perhaps a creepy warehouse rave. Neither is true of Saturday’s Scion Exposed tunnel party, which is literally underground, at 220 Central Ave. beneath the Second Street overpass. Part car show, part concert, Scion Exposed features a pop-up skate park, food trucks, drinks and more, all free from 2 p.m.-midnight. RJD2 headlines the music stage with support from Chairlift, DAAP Girls and more performing throughout the day. RSVP here for free admission; Scion owners get advanced entrance at noon. Celebrate Halfway to St. Patrick’s Day during the Cincinnati Celtic Festival Saturday and Sunday. The free fest moves from Fountain Square to Washington Park this year, but continues to celebrate all things Celtic with plenty of music, food and entertainment. Knock back some Guinness, cheer on Irish dancers and get jig-y to the sounds of bagpipes between noon and 10:30 p.m. both days. With local Celts taking over the park, this month’s City Flea moves up the street to the lot at Twelfth and Vine. Vendors will be hawking everything from clothing and accessories to home goods and fine art from 10 a.m. to 4 p.m. The City Flea is a fun one-stop spot to support local artisans and sellers all under one roof. Sans roof. Downtown isn’t hogging all the fun this weekend — Milford’s Longstone Street Festival brings more than 15 area bands to the ‘burbs Saturday. Area musicians will perform on two stages along Main Street where kid-friendly activities await (we’re talking a Velcro wall, bungee joust, rock climbing and more). Saunter through historic downtown Milford, stop in a few shops and restaurants and enjoy the music from 11 a.m.-11 p.m. The fun continues west at the Westwood Art Show, 11 a.m.-5 p.m. Sunday. More than 70 artists, crafters and DIY-ers will be selling goods including photography, re-purposed jewelry and accessories, woodwork, sculptures, pottery, edibles and more. This weekend’s theater offerings include Ensemble Theatre’s Good People, The Three Musketeers at Playhouse in the Park, To Kill a Mockingbird at Cincinnati Shakespeare Company and Covedale’s Cat on a Hot Tin Roof. Peep the links for our reviews of each.Browse our calendar for other events, art exhibits, volunteer opportunities and more to do this weekend.

After a long hot summer (well, it's still feeling like a long hot summer), we have a full array of shows onstage in Cincinnati for you to choose among. I've seen two of them so far: Good People at Ensemble Theatre Cincinnati and The Three Musketeers at the Cincinnati Playhouse in the Park. ETC's production of Pulitzer Prize winner David Lindsay-Abaire's 2011 piece (this is the regional premiere of Good People, which was nominated for a Tony a year ago) about a woman who falls off the bottom of the employment ladder has enough humor to be entertaining (especially with Annie Fitzpatrick in the central role of Margie and Kate Wilford and Deb Girdler as her gossipy friends and bingo-night comrades) and enough contemporary relevance to be thought-provoking. ETC's D. Lynn Meyers is at her best staging naturalistic shows with social meaning, and that's exactly what this one offers. It has a great cast and flexible, attractive scenic design by the ever-creative Brian c. Mehring. I gave it a Critic's Pick. Through Sept. 23. Review here. Box office: 513-421-3555. I wanted to love The Three Musketeers at the Playhouse (through Sept. 29), but its balance of humor and heart is out of whack to my tastes. There's lots of adventure, hilarity and laughter — especially some no-holds-barred swordplay — but the show tries to hard to entertain that it misses out on the true emotion that should lie beneath. I suspect many people will love this thrill-a-minute tale of political intrigue and valor, loyalty and royalty in 17th-century France, and perhaps it will evolve to deeper feelings as it runs. I love new Artistic Director Blake Robison's desire to put appealing, family-friendly work onstage, and he's using this production to show what he means. I hope his approach gets a tad more texture and depth as his tenure continues. Review here. Box office: 513-421-3888. I haven't yet seen To Kill a Mockingbird at Cincinnati Shakespeare Company, and their publicity says it's already sold out its first-two weekends. So you might want to put that one on your calendar for sometime before it wraps up (Sept. 30). In the meantime, you might want to head to Washington Park on Sunday evening at 7 p.m. for a special free presentation of CSC's touring production of The Tempest. It's a perfect piece for outdoor performance, set on an island with a sorcerer and his lovely daughter and some shipwrecked nobles who are responsible for his exile. Audience participation will be a key component of this event, with the audience asked to create large-scale effects by blowing bubbles, making waves with silk and generating sound effects. Sounds like great fun. Music (by The Young Heirlooms) begins at 6 p.m. This is a good one to bring kids to see. Also off and running this weekend is Cincinnati Landmark's production of Tennessee Williams' Cat on a Hot Tin Roof. It's a classic drama of sexual tension and family strife, a bit heavier fare than is usually found at the Covedale Center. It's a sign of the company's ambition to be a full-fledged theater offering a wide range of material. (Through Sept. 30.) Box office: 513-241-6550.

There's a new piece of musical theater in the oven, and you'll be able to get a peak and a listen on Sunday, Oct. 7 at 7:30 p.m., when it has a one-night-only public performance at Covington's Carnegie Center. The evening will feature several local theater veterans including two with national reputations, so it's a very promising event. The Sandman is a new musical by Richard Oberacker and his writing partner Robert Taylor. They teamed to create Ace (which premiered at the Cincinnati Playhouse back in 2006), and Oberacker was the creative force behind Don't Make Me Pull This Show Over, a hit at the Cincinnati Fringe in 2008 and returned for a full production at Ensemble Theatre the following season.The Sandman is strange and darkly comic musical, drawn from a nightmarish fantasy by E.T.A. Hoffman, the author of the story of The Nutcracker and the personal inspiration for the opera The Tales of Hoffman. Oberacker, whose day job is as a music director with Cirque du Soleil in Las Vegas, will spend a week here to workshop the show about a month from now, and he will play piano for the performance on that Sunday evening. A star-studded cast has been recruited, topped by Broadway veteran, Tony nominee and nationally respected musical performer Pamela Myers. She'll play Frau Kaeseschweiss, an unusual nanny recruited to serve as a nanny the children of the Strauss family. Charlie Clark and Sara Mackie (both Cincinnati veteran theater professionals and familiar to ETC and Carnegie theater audiences) will play the parents, with Clark as an ingenious German clockmaker who sets in motion a series of bizarre and unnatural events when he meets the strange Dr. Copelius, played by Bruce Cromer. (Cromer is spending this month at Cincinnati Shakespeare as Atticus Finch in To Kill a Mockingbird). The devilish deal between them to save the Strauss's daughter's life takes a strange and chaotic turn and sinister forces at play are revealed — forces from which only the children may be able to save their parents. Another piece of good news: Busy local director Ed Cohen will be involved in staging the piece, which will utilize a number of projected illustrations to evoke the mood and setting.Oberacker is excited by the quality of the cast assembled for the performance, especially with Myers' involvement. (Like him, both are Cincinnati natives and grads of UC's College-Conservatory of Music. She was the first musical theater grad in 1969; although he was a musical prodigy, conducting shows for community theaters while still in high school, he excelled in CCM's drama program, graduating in 1993.) In a recent email, he told me that Myers is playing "a titanic role that narrates the whole show" and added that it's "huge to have Pam in a role tailor made for her." The Carnegie's website has the performance listed but no further information. If you want to be there, I suggest you call the box office and make your interest known: 859-957-1940.

OK, it's the last day of August and the last true weekend of summer. That typically means there's almost no theater, since most of the stages in town are readying their season openers. But you do have a few choices: At the Clifton Performance Theatre you can see the last few performances of Nothing, a production brought back from this year's Cincinnati Fringe Festival. It's a one-man show about bullying and autism, told with lots of illustrative video. It was a popular item during the Fringe in June, so it's certainly worth checking out. Tickets: 513-861-7469. Another Fringe-like option this weekend is a mash-up of OTR Improv and True Theatre, happening at Know Theater, which is kind of like the crazy uncle of these two groups that make the Over-the-Rhine venue their home. On Saturday evening at 8 p.m., they'll present another installment of The Chronicle, a long-form improvisation based on the real-life stories of special guests. Dave Levy and Jeff Groh, the guys who make True Theatre go, are the starting point for the evening's fun and games. They'll tell stories, and then the improv folks will turn them into something more. You can get tickets (for $5) at the door — located at 1127 Jackson Street in OTR. The Cincinnati Playhouse in the Park opens its new season (with a new artistic director) next Thursday with The Three Musketeers. But here's a tip: You can see previews starting Saturday, and tickets are more affordable than during the actual run of the show. You might know the story of D'Artagnan and his three swashbuckling buddies, Athos, Porthos and Aramis — but I bet you've never seen such a rollicking, have-a-great-time production as this one. I just finished reading the very conversational and funny script, and I suspect that audiences will love this show, especially if it's pulled off with visual panache. It's our first chance to see a work directed by Blake Robison, the new guy in charge. He says this is the kind of work he wants to bring to the stage regularly. Be among the first to see what he's up to. Box office: 513-421-3555. Other theaters opening shows next week include Ensemble Theatre Cincinnati on Wednesday (Good People is about unemployed folks dealing with the "new normal") and Cincinnati Shakespeare Company starts its production of To Kill a Mockingbird on Friday. Both productions have fine casts: Annie Fitzpatrick is playing the hard-pressed central character in Good People; Bruce Cromer is the virtuous attorney Atticus Finch in Mockingbird. Both are among our most watchable actors. My Curtain Call column in CityBeat this week offers more about these shows and others that are opening this month.