60 Minutes II Correspondent Vicki Mabrey reports from New York.
But not everyone is wild about the unassuming, 40-year-old native New Yorker. Many critics have condemned him.
His first musical, Jekyll and Hyde, is a bodice-ripping, gothic melodrama filled with songs that sound like pop hits. And Wildhorn's shows draw audiences raised on pop music and rock 'n' roll concerts - the kind of audience that Wildhorn investors such as Freddie Gershon are counting on.
"He's producing a minor miracle by bringing in a new theater audience," Gershon says.
"They've been raised in the record business. They've been raised with the world of pop music, where music has become a dominant force in their lives," he says.
His audience also adopted Wildhorn's second production - a comic operatic version of another familiar story - The Scarlet Pimpernel.
And last spring, his latest show, The Civil War, gave Wildhorn three musicals playing on Broadway at the same time. That one didn't last long. Bad reviews and poor ticket sales forced the show to close down after two months.
If Wildhorn's show tunes have a familiar sound, it's probably because he had a very successful first career writing radio-friendly ballads. Not only has he written hits for Whitney Houston, he has penned thousands of songs, hundreds that have been recorded.
The catchy tunes and familiar story lines that his fans love are exactly what the critics hate. The New York Times' critic called Jekyll and Hyde "leaden." The New York Magazine critic even scolded the audience for liking the The Civil War.
Newsday's Linda Winer has written some of the most scathing Wildhorn reviews: "Frank Wildhorn writes gallumphing, dunderheaded musicals that make everything by Andrew Lloyd Webber seem like great art."
Winer calls them paint-by-numbers stories punctuated with big tear-your-guts-out popular songs.
"The problem is that the music tends to sound all the same," she says. "They're all climax, after climax, after climax."
"They tend frequently to be dropped into the middle of the show, without really fitting organically into the dramatic material," Winer explains.
Wildhorn says Winer doesn't know what she is talking about. Still, he admits that he wants good reviews.
He spends as many as 12 hours a day at his piano. Of the melodies he comes up with, he says, "They're in me. When I sit at the piano, they're already there. And my job is to find them."
Wildhorn wrote Jekyll and Hyde while at the University of Southern California. He spent the next 11 years finding a theater willing to produce it. Then, when he was searching for a str, a friend gave him a tape of the winner of a Starsearch competition.
He cast that woman, Linda Eder, as the female lead in Jekyll and Hyde. She became his muse, and last year, his wife. When he writes, Wildhorn says, he hears Eder's voice.
But she is more than a muse to him. "She's the one that gets me to slow down," he says.
Wildhorn has a 13-year-old son from a previous marriage. In August, Eder gave birth to the couple's first child.
Despite their love of music Wildhorn and Eder are in many ways opposites. Even as the critics savage him, they rave about her, comparing her voice to Streisand's. He's the driven one, while she's a reluctant diva, who prefers the quiet of their country home.
Eder credits him with believing in her when she was unknown. This confidence kept them touring the country - building an audience for Jekyll and Hyde before arriving in New York.
Still, Jekyll and Hyde ran for three years before it turned a profit on Broadway. The Scarlet Pimpernel has closed and reopened twice, arriving this fall in a smaller theater.
So why do investors, such as Gershon, who gambled $1.5 million, keep backing Wildhorn?
"The key to a musical is not the Broadway experience; it's what happens after Broadway," Gershon says.
"The tour, the foreign licensing, and even more important than that is, Will it be played in a dinner theater, a regional theater, a college or high school production in five years, in 10 years, in 15 years, in 25 years?" he asks.
So the effect of the Wildhorn way, to the dismay of his critics, has been to shrink the stature of Broadway. The Great White Way has been reduced to a steppingstone to another more profitable life.
"Much to everyone's astonishment, all the king's horses and all the king's men can't kill the guy," Winer says. "You know, he keeps bouncing back with more shows!"
So while the theater world is still wondering what to make of his musicals, Wildhorn is at home with Eder coming up with their next show. Havana will be a vehicle for Eder as she plays a big band singer who ends up in a nightclub in Havana in 1948.
After Havana, Wildhorn wants to stage musical versions of Alice in Wonderland, Dracula, and the movie Blade Runner.
"I'm a man of the people," he says. "I'm not a sophisticated theatergoer. I love good melody and good harmony. I want to hum the tunes myself."
"I want to be passionate. And if that's what's happening in the show, that's a great thing," Wildhorn adds.
Produced by David Kohn