That you can write a play about just about anything and everything is one of the more fascinating characteristics of the theatrical stage.

To wit, “Every Brilliant Thing,” through June 19, Schubert Theatre, Labuda Center for the Arts, for the 31st season of the Pennsylvania Shakespeare Festival (PSF), DeSales University, Center Valley.

Suzanne O’Donnell, a PSF veteran actor, plays the role of narrator in the 90-minute production (without intermission).

The show recounts a daughter’s experiences, beginning at age six, when her mother is apparently hospitalized for depression.

The show was originally performed at the Ludlow Fringe Festival (2013) by British comedian Jonny Donahoe and written by Duncan Macmillan. It had its North American premiere at Barrow Street Theatre, New York City, where it was filmed for HBO (2016).

True to its form, the PSF production includes audience interaction, lots of audience interaction, including some attendees asked on stage. Audience participants were quite good, June 10, when the performance was seen for this theater review.

At the start of the show, select theater-goers are given cards with a number on each. When a number is called out by O’Donnell, the person reads what’s on the card.

It might be a remembrance, an observation or a “thing,” all part of “Every Brilliant Thing” the girl put on notes at her mother’s pillow in an attempt to cheer her up.

The self-referential play is explained every step of the way, so no one need to feel nervous about his or her debut on the PSF stage.

“Everyone is going to want to hear the brilliant thing that is on the card,” O’Donnell says, coaching participants to project their voices. “And some of you will join me on stage.

“The play embraces the full spectrum of life,” O’Donnell reassures, and cautions.

The play is augmented by snippets of a few well-known songs, including “They Can’t Take That Away From Me.”

“Every Brilliant Thing” is “My Favorite Things” from “The Sound of Music” (1959) meets a one-person “Our Town” (1936).

At the heart of the PSF production is O’Donnell, confident and wise, affectionate, with bright-eyed enthusiasm, jumping for joy and giving sensitive asides. She’s a counselor off the clock. No couch. Call it stand-up therapy.

O’Donnell ad-libs with the audience, ever in the moment.

Director Anne Hering gives O’Donnell the freedom to be herself. The play, the performance, the direction is very authentic. David Greenberg is Sound Designer.

If “all the world’s a stage,” as Shakespeare put it (“As You Like It,” Act 2, Scene 7), the men and women in the audience of “Every Brilliant Thing” are more than “merely players.”

There’s a puppy dog (an audience member’s sweater cradled in O’Donnell’s arms) amusingly named Sherlock Bones. Someone plays the veterinarian. Another plays a professor (A sock puppet from an actual sock once removed is produced.). There’s “Dad,” too. Each a “player” in the performance.

The list of “brilliant things” (ice cream, roller coasters, etc.) grows to 654, to 700 and more.

At the play’s conclusion, you, too, may be looking to your life and that of family and friends to begin your own list of “things” you most value.

Afterward, outside Labuda, the setting sun was doing its thing, sending every rainbow band of color, writ large along South Mountain. Brilliant.

Tickets: Box Office, Labuda Center for the Performing Arts, DeSales University, 2755 Station Avenue, Center Valley. https://www.pashakespeare.org/ 610-282-WILL (9455)