One of the most interesting documentaries of the year had nothing to do with health care or Iraq.

ShowBusiness: The Road to Broadway sort of slipped in and out of theaters without a whole lot of fanfare, which is really too bad because director Dori Berinstein has created a fascinating glimpses behind the scenes of four major musicals opening in New York during the 2003-2004 season.

Luckily, the movie came out on DVD this week (Liberation Entertainment, $28.95).

For her movie, Berinstein picked four musicals to follow, and boy did she pick good ones: Wicked, Avenue Q, Caroline, or Change and Taboo.

Bay Area audiences, of course, got the first look at Wicked during its pre-Broadway tryout. We had the great fortune to see Caroline, and Avenue Q made its overdue local debut last August. The only real mystery in this bunch is Taboo, the Rosie O’Donnell-produced ’80s flashback revolving around Boy George: his life, his music and himself (he was in the cast).

Of the four, Wicked and Avenue Q were monster hits and are still running. Caroline is an esteemed flop by Angels in America playwright Tony Kushner and composer Jeanine Tesori. And Taboo is known as one of Broadway’s great disasters.

The movie follows each of the shows from the summer of 2003 up to the Tony Awards in 2004 when Avenue Q upset favorite Wicked for the Best Musical award.

Along the way, we get fascinating glimpses of the creative process, the marketing machine and the economics of Broadway. One of the juiciest threads involves tension between Jeff Marx, the co-composer of Avenue Q and Jeff Whitty, the book writer who was brought on board relatively late in the creative process.

It all ends happily, with Tony Awards for everyone, but the two did not get along, and it’s not pretty. Marx’s parents, by the way, turn out to be a highlight of the movie.

Director Berinstein includes several round-table discussions with New York theater critics, and this, to me, is a horror show. These nattering fools (save Charles Isherwood from the New York Times, who salvages a shred of dignity) make critics look like the lowest possible bottom feeders in the show business pool. Ouch.

Covering such a diverse assortment of shows, Berinstein ended up with more than 250 hours of video that had to be whittled down to 104 minutes.

“The season was a roller coaster with highly anticipated shows closing early and little shows coming out of nowhere to take Broadway by storm,” Berinstein says. “There was no way to predict where the Season was heading. Consequently, it was necessary to capture everything. Editing, as a result, was a massive and extremely difficult process. Narrowing down our primary storytelling to four musicals was excruciating. So many extraordinary moments are on the cutting room so to speak. I can’t wait until we assemble the DVD.”

Visit the movie’s official site at www.showbusiness-themovie.com.

Here’s the trailer from ShowBusiness: The Road to Broadway, followed by a clip featuring Idina Menzel of Wicked.