ESSEX —The Ivoryton Playhouse and director/choreographer Todd Underwood are giving “A Chorus Line” a sparkling production through Sept. 2. Whether or not you have seen the classic musical before, you’ll be glad to meet this uniquely gifted group of singer/actor/dancers.

Like Zach (Edward Stanley), the director who is determined to create the strongest possible ensemble, Underwood has made terrific casting choices.

Famously, the show is based on a series of workshops, taped during 1974, in which a group of young New York performers talked about the impact of the theater on their lives. Michael Bennett claimed the show as his conception (he certainly directed and choreographed the original), but over the years his total artistic control has been questioned. James Kirkwood and Nicholas Dante wrote the book, with the great Marvin Hamlisch composing the music, and Edward Kleban providing the lyrics. The longest running show in Broadway history until “Cats” outran it in 1997, and the winner of the 1976 Pulitzer Prize for Drama, “A Chorus Line” was, and continues to be, “one singular sensation.”

The plot is deceptively simple: in an austere rehearsal hall, a group of performers audition for a few spots in the chorus of a big show: the chorus, as Zach tells them, “backs the star” with “perfectly unison dancing.” Because the chosen dancers and the director will be working so closely together, Zach demands that each hopeful tell him a personal story that he won’t find on a resume. And the stories are instantly so fascinating, heart-breaking, and in some cases, hilarious, that we are quickly honored to learn all we can about how these young people got to this stage.

Nearly every one of the performers here is deserving of praise, but there are, inevitably, several who stand out. Dakota Hoar, as Mike, who begins with the charming, “I Can Do That,” certainly can do a terrific tap routine and present a winningly innocent young man. Lili Thomas, as Sheila, whose aggressive facade masks deep-rooted childhood pain, nails every one of her lines and emotions, and performs her signature song, “At the Ballet” beautifully, with the help of the touching Kayla Starr Bryan (Bebe) and Liv Kurtz (Maggie). Ronnie S. Bowman, Jr., is electrifying as Ritchie, and Cory Candelet, as Don, is every inch the Kansas City boy (I know whereof I speak), and a magnetic dancer.

Some numbers are written as show-stoppers, and “Dance: Ten; Looks: Three” is certainly one of them, especially as performed with joyful dynamism by Alexa Racciopi (Val), whose sheer gutter-mouthed glee is irresistible. And while Underwood hasn’t helped Natalie Madlon’s Diana find the youthful energy and humor in “Nothing,” her sober rendition of the central “What I Did For Love” is a beautiful example of a skilled actor avoiding sentimentality so that the audience feels the emotion.

Another example of this skill comes from Joey Lucherini as Paul, who has a wrenching monologue that could easily slide into self-pity. Lucherini, though, simply recounts the facts (though there is nothing simple about the acting mastery required here) — and in doing so, he allows us to absorb every complex and heart-rending moment.

The production has a few flaws. Stephanie Genito, as Cassie, dances beautifully, but she hasn’t found the fragility of a woman who has failed spectacularly and is begging for a way back to the only life she wants. And in casting an older Zach (Edward Stanley), Underwood blurs the sharp pain of their relationship. Elsewhere, though, Stanley vividly conveys Zach’s dominance, and he plays his moment with Paul to perfection.

On opening night, lighting troubles cast some featured actors in shadow, and sound difficulties rendered some of the appropriately softer moments almost inaudible. However, the miracle of getting the whole cast onto this small stage without crowding, the energetic band led by Michael Morris, and Underwood’s compelling choreography easily overcame these moments.

And this cast, with only a few exceptions, is one of the most winning I’ve seen, outside of the Broadway original and revival. Thanks to their energy and commitment, I feel that I know them—their characters—and this feeling is the heart and soul of “A Chorus Line.”

“A Chorus Line” will be playing through Sept. 2. Tickets are available by calling the Ivoryton Playhouse box office at 860-767-7318 or by visiting the website at www.ivorytonplayhouse.org (Group rates are available by calling the box office for information.) The Playhouse is located at 103 Main Street in Ivoryton.