Shakespeare drew his inspiration from libraries of the classics; musical theater writers often draw their inspiration from the libraries of movie studios. Scouring the film libraries, Broadway producers have culled ideas for new musicals: “Hairspray,” “The Producers,” “Lion King” and “Big.” In this respect, 2005 might seem similar to years past. Half of the four Tony Award-nominated musicals traced their origins to films. “Spamalot” and “Dirty Rotten Scoundrels” joined with “La Cage aux Folles” and other adaptations for the season.

But at least one of these shows was different than the rest. “Spamalot” might better be called “inspired by” the classic Monty Python movie. Eric Idle uses the basic setting and cast of characters that he and the other Pythons created 30 years ago, but fashions a whole new structure around the “Holy Grail” skeleton.

Last year was also a banner year for more original work — from “The Light in the Piazza” to “The 25th Annual Putnam County Spelling Bee.” “The Light in the Piazza,” composed by Adam Guettel ’87 and starring Victoria Clark ’82, have added a more serious touch to the Broadway musical. Given the prevalence of musical comedy on Broadway in recent years, there is some truth to this common conception that musicals are simply silly entertainment.

While Guettel succeeded in creating more than a silly piece of work, often his work gets overly caught up in itself, sacrificing the expression of beautiful ideas and melodies. “Piazza” also showcases the maturation of the playwright, heir to a considerable legacy in musical theater as the grandson of Broadway lyricist Richard Rodgers and son of Mary Rodgers, who wrote the lyrics for “Once Upon a Mattress.”

The evolution of the New York stage can also be seen in other shows from this season. Critical acclaim, at least, greeted a revival of “Sweeney Todd” that required cast members to double as the orchestra. Stars Michael Cerveris ’83 and Patti LuPone play the guitar and tuba, respectively.

Producers on Broadway are always concerned with broadening the audiences that come to the theater by attracting newcomers. This past year, some of the most successful shows succeeded because they represented new twists and attractions drawing in new audiences.

“Spamalot” demonstrated this most clearly through its success in bringing men to the theatre. Often Broadway has been stereotyped as a medium that caters to the effeminate, but the gut laughter evoked by Monty Python has drawn men into the theater.

“The Color Purple” also represents a broadening of the typical Broadway base. The story of the struggle and lives of African-American women is showcased in the show. The creators also made deliberate choices in opening the already acclaimed story to a whole new audience: African-American men.

“Spelling Bee” also recognized new ways to appeal to different audiences. The show has several different R-rated versions, where the vocabulary becomes more risque. This leaves options for both more adult and family-oriented audiences.

This year, Disney titles will lead the way with at least two new adaptations of feature films. First in the spring is “Tarzan,” a stage production of the 1999 animated feature. Following this will be a transfer from London (in more ways than one) of “Mary Poppins.”

And of course, the other film adaptation readying to strike is “The Wedding Singer,” based on Adam Sandler’s 1998 movie.

At this time last year, some questioned whether the straight play had a commercial future on Broadway. Even Pulitzer Prize winner August Wilson had difficulty finding money to back his final production on Broadway. Later in the season, however, the commercial successes of “Doubt and the Pillowman” demonstrated that dramatic plays — not just musicals — may also still have a future on Broadway.