by Clark Groome

Most of the audience knows what’s going to happen before they enter the Walnut Street Theatre for its music adaptation of Erich Segal’s novel “Love Story.” Not only was Segal’s book immensely popular, so was the 1970 movie that starred Ali MacGraw and Ryan O’Neal. Now it’s a musical.

With a book and lyrics by Stephen Clark and music and additional lyrics by Howard Goodall, “Love Story” tells the tale of the Harvard pre-law preppy jock Oliver Barrett IV falling in love with the Radcliffe music major Jenny Cavilleri.

The young lovers come from vastly different backgrounds: he from wealth and an upper class family that finds it hard to express feelings; she from an Italian working class family that is nothing if not about communicating.

The romance, for all the problems caused by Oliver and his father’s inability or unwillingness to tell the other that he’s loved, is a thing of beauty.

As their life together seems to be sailing along with nothing but a bright future, tragedy strikes. At 25, Jenny is diagnosed with incurable leukemia.

From the joys of the story’s beginning to the sadness of the story’s ending, those watching the Walnut’s superb production are, let’s be honest, shamelessly manipulated. Laughter turns to tears right on cue.

All of the central performances — Will Reynolds as Oliver, Alexandra Silber as Jenny, Paul L. Nolen as Oliver’s father and especially Charles Pistone as Jenny’s dad — are first-rate. Their characters are fully developed, and their interaction is credible from beginning to end. Good singers all, the Goodall score, while generic and not particularly memorable, is beautifully performed by the principals and the seven members of the ensemble who serve many functions from doctors to waiters to hockey fans at Oliver’s Harvard game.

In an inspired bit of staging, director Annabel Bolton has placed music director Douglas G. Lutz and his six string-playing orchestra members on stage. Since music plays such a large part in Jenny’s life, this was both appropriate and extremely effective.

Peter McKintosh (set), Shon Causer (lighting), Colleen Grady (costumes) and Will Pickens (sound) designed the simple but attractive production.

My one gripe is that the show opens as is ends: at Jenny’s memorial service. Giving away the ending before the story is told always bothers me, which is why, mystery buff and Peter Falk fan that I am, I never liked TV’s popular “Columbo.” If people know what happens from reading the book or seeing the movie, fine. Just don’t tell those who don’t know what’s going to happen 100 minutes later.

Other than that, the Walnut’s “Love Story” works very well. If you go, don’t forget the Kleenex.

For tickets toLove Story,playing through Oct. 21 at the Walnut Street Theatre, call 215-574-3550 or 800-982-2787 or visit www.walnutstreettheatre.org