“Spring Awakening” is an unusual musical, although a very successful one. The original Broadway production won eight Tony Awards in 2007, including Best Musical.

The plot is based on a 1891 play of the same title. As the name suggests, it is a coming-of-age story about adolescent sexuality, based on the conservative morals of a provincial town in 19th century Germany.

In The Pennsylvania Playhouse production of “Spring Awakening,” continuing through June 14, nearly the entire cast of 17 are adolescents, or at least they appear to be, and they are all fabulous vocalists.

Unlike too many musicals of this century, the soft rock music by Duncan Sheik, with lyrics by Stephen Sater, is uniformly beautiful, closely following the emotions aroused by forbidden love.

The book by Sater is centered around the education of teenagers, ruled by harsh teachers who demand repetition of Latin phrases and complete obedience. Sex is a mystery, and repression is a burden.

In the May 29 performance seen for this review, the actors, led by Joshua Bridges (Melchior), Tahlia Colon (Wendla), Gray Pescatore (Moritz), Hannah Cummings (Ilse) and Bee Core (Martha), captured the strong emotions with stirring vocals and acting.

The best moments might be the singing by the whole cast, with a wonderful blending of parts. The only downside was that the lyrics could not always be heard clearly.

Music Direction is by Tony Moore. Costume Design is by Zoe Mulzet and Todd Burkel, Choreography is by Maxwell McCurdy.

The staging by Set and Lighting Designer Brett Oliveira is simple and effective. It is not changed throughout the nearly two-and-one-half-hour production. There is a church window in the middle, flanked by pictures of rows of books to indicate the academic environment.   

“Spring Awakening” contains a warning about sexual content and abuse. The controversial parts are toned down and seem to be much tamer than in other versions. But there is no doubt about what is being portrayed. This play does not hesitate to present difficult and painful realities.

Directed by Katelyn Morgan, the production uses the vitality of its cast to portray the confusion and urgency of eternal awakenings that young people still struggle with today.

“Spring Awakening,” 7:30 p.m. May 29, 30, June 5, 6, 12, 13; 6 p.m. May 31, June 7, 14, Pennsylvania Playhouse, 390 Illick’s Mill Road, Bethlehem. 610-865-6665, http://www.paplayhouse.org/