The formula for making popular music used to be simple and nearly uniform: Take four guys who can sing in perfect harmony. Add hair tonic and dinner jackets. Record and repeat. Results: “Forever Plaid.”

The long-running off-Broadway musical comes to the Mendel Center Mainstage at Lake Michigan College at 7 p.m. Sunday, Oct. 10.

It was an era of innocence, sincerity and music that stood on its own — without the help of synthesizers and vocal correction. In the 1950s, clean-cut guy groups such as the Four Aces and the Four Seasons dominated the airwaves and captured the affections of schoolgirls everywhere. Now, baby boomers — and their children and grandchildren — can take a trip back in time to music’s glory days thanks to “Forever Plaid.”

Funny, uplifting and wholesome, “Forever Plaid” tells the story of four velvet-voiced high school friends whose dreams of making the big time are cut short by a car accident. Through a miraculous turn of events, the four find themselves back on stage with the chance to perform a concert for the ages. The nerdy but lovable singers give their all as they pursue one last shot at realizing their dream.

Throughout the show, audience members will tap their feet as the guys deliver silky songs in perfect pitch. They’ll also be smiling at the quartet’s charmingly cheesy choreography and laughing at their witty banter.  Familiar to many who grew up in the 50s, and still beautiful, the songs include “Three Coins in the Fountain,” “Chain Gang,” “Heart and Soul” and “Love Is a Many Splendored Thing.”

“Forever Plaid” has been a top-grossing touring production, collecting legions of die-hard fans along the way. Recently the musical celebrated its 20th anniversary with the release of a DVD special. Cast members have harmonized for presidents, dignitaries and international audiences since the musical opened in New York in 1990.

Tickets for “Forever Plaid” are available by calling (269) 927-1221 or visiting www.lmcmainstage.org.  Students (kindergarten through college) and seniors (60 and older) receive 10 percent off single-ticket prices. Groups of 20 or more can receive a 15 percent savings on ticket prices.

For more information about group rates and special arrangements, call the group coordinator at (269) 927-8109 or e-mail questions to groups@lakemichigancollege.edu.

The “Forever Plaid” performance is sponsored by Chemical Bank.

The 1,517-seat Mendel Center Mainstage Theatre offers state-of-the-art acoustics and comfortable seating in elegant surroundings. Other amenities include free, lighted parking; handicap accessibility (inside and out); an array of special services; and friendly ushers and support personnel.

The Mendel Center is within a 30-minute drive of Niles and within a 40-minute drive of Kalamazoo or South Bend. Located on the Napier Avenue campus of LMC, the Mendel Center is one mile east of I-94 on Napier Avenue (Exit 30) in Benton Township.