The scene is a cramped apartment. Two aspiring writers, early 30s, sit at an upright piano, rehashing a song for a musical they’ve been working on for years. They’ve had a few readings, even a workshop. But how are a couple of unknowns going to get this musical from their living room to Broadway? (Okay, they’ll take off-Broadway.)

The answer, for a growing number of hopefuls, is the New York Musical Theater Festival. Getting a deluged producer even to listen to your CD might be nigh impossible, but the equal-opportunity NYMF takes a close look at every entry it receives through its open submissions channel. This year, from a pile of about 400 submissions, 15 musicals will receive full productions at the third annual festival, which began on Sunday and runs through October 1. (An additional 19 original musicals appear as part of the festival’s Invited Works series.)

Getting into the festival is a major break for anyone who’s not “one of the three people who is regularly produced,” NYMF’s executive producer, Isaac Hurwitz, said. Of the 70-odd shows produced during the first two festivals, eight either have already had a New York transfer or have one scheduled, including “Shout! The Mod Musical,” “The Great American Trailer Park Musical,” the acclaimed “[title of show],” and the smash off-Broadway hit “Altar Boyz.”

In many ways, the story of the “Altar Boyz” team fits a common NYMF profile. The songwriters had worked regularly in Broadway orchestra pits; the book writer had written for stage, TV, and film. Accomplished, but still unproven as musical writers, they needed to convince investors that audiences would respond to their satire of Christian boy bands.

“What NYMF provided was an opportunity to get the show up in front of an audience — no scripts, no music stands,” Mr. Hurwitz said. “A three-dimensional realization.”

During the first NYMF in September 2004, audiences lined up hours in advance to wait for returns at sold-out shows. The rest is history: “Altar Boyz” transferred to Dodger Stages, where it’s still running, 18 months later.

Such lore fuels the ambitions of hard-scrabble musical theater writers everywhere, many of whom see NYMF as their best (and perhaps only) shot at getting their musical from page to stage. Hence the 400 envelopes that arrived at NYMF’s New York offices last March, each one carrying the product of hundreds of hours of unpaid work.

The open submissions pile constitutes a kind of unofficial survey of today’s musical writers and their influences. “Lately, we’re seeing a lot more musicals in a contemporary musical style, not just the classic Rodgers and Hammerstein sound,” the executive director of NYMF, Kris Stewart, said. “There’s a lot of work that can only belong to this moment in history — whether that’s because of its political content or its very current vernacular.” According to Mr. Stewart, the average submission comes from a team of writers in their late 20s or early 30s, “a generation that has different musical reference points” than Richard Rodgers or Stephen Sondheim.

One such team is behind this year’s “Smoking Bloomberg,” a satire about a Korean dry cleaner whose business is destroyed by the mayor’s anti-smoking campaign. New Yorkers David Cornue, Sam Holtzapple, Warren Loy, and Chris Todd — all in their late 20s to late 30s — wrote the bulk of “Smoking Bloomberg” in Mr. Cornue’s Midtown studio apartment. Mr. Loy cheerfully calls the project “an oldfashioned book musical with a modern sensibility and a whole bunch of bad words.”

Like many of his peers, Mr. Loy is not interested in writing G-rated shows. “Content that has been in stand-up comedy for 50 years has been largely absent from mainstream musical theater,” he said. “I think audiences are hungry for musical theater to grow up a little bit.”

Mr. Loy said that the movies like “South Park: B igger, Longer, and Uncut” and TV shows like “The Family Guy” have influenced his team as much or more than Broadway shows.But if there’s a show on the Great White Way that gives hope to the writers of “Smoking Bloomberg,” it’s “Avenue Q,” another offthe-wall, not-for-kids musical comedy set in a crazy, inexhaustible city. Like “Avenue Q,” “Smoking Bloomberg” puts subversive lyrics in relatively conventional song structures.

Similarly, the team behind the new musical “Oedipus for Kids!” takes its button-pushing tale — of a children’s theater troupe putting on a musical version of “Oedipus”— past the boundaries of traditional Broadway taste. Composer Robert Saferstein set Kimberly Patterson and Gil Varod’s discomfiting lyrics (“My Lover is My Husband is My Son”) to childhood ditties. And “The Children,” another entry from writers in their late 20s, is a riff on a 1980 B-horror movie in which schoolchildren turn into zombies and go after their parents.

But while satire has been hot for the past few years, especially after the success of “Urinetown,” Mr. Hurwitz says he’s seen a recent shift away from satirical content. “This year,” he said, “there’s a return to sincerity.”

In that vein, this year’s slate includes “Emerald Man,” a “comic book Don Quixote” with a pop–rock score and a heartfelt message about the power of optimism, and Barbara Schottenfeld’s “Hot and Sweet,” which follows an allgirls’ 1940s big band, the Honeytones, while the boys are overseas. Ms. Schottenfeld is among a group of writers distancing themselves from the tongue-incheek approach. Her show, she says, is “clever and witty, but also deeply human.”

And although on the surface “Go-Go Beach,” a musical based on bad ’60s beach party films, might look like another ironic send-up, John Wimbs, its book writer, says the show is a “loving, valentine-style period piece” that embraces — rather than spoofs — its surfer kids, following the beach party gang from early ’60s innocence through late ’60s disillusionment.

“Go-Go Beach” is also typical of another NYMF trend — the journeymanlike flexibility of today’s emerging songwriters, who, Mr. Hurwitz notes, are often willing to write songs in “whatever genre best serves the story.”

So while composer David Friedman is best known for his cabaret tunes and inspirational ballads, he didn’t hesitate when co-writer Peter Kellogg asked him for a country-and-western score for the new comedy “Desperate Measures.” After all, for his last musical, “Chasing Nicolette,” Mr. Friedman wrote a “13th–century, slightly medieval” score.

Similarly, the Nashville-based songwriter Marcus Hummon is known for his Grammy-winning country and pop songs. But for his new Jim Thorpe musical, “Warrior,” Mr. Hummon created a score that encompasses Native American chanting, bluegrass, New Orleans, ragtime, and boogie-woogie.

The new “Party Come Here,” a collision-of-religions comedy set in Rio,”has a bossa nova feel running through the whole score,” said book writer Daniel Goldfarb. But like many of his peers, Mr. Goldfarb is a realist about the slim odds of getting any original musical mounted. So while penning “Party Come Here,” he also worked on a musical set in the ’60s. “You go back and forth between your bossa songs and your Supremes-like songs,” Mr. Goldfarb said cheerfully. “You never know what’s going to get picked up first.”

Through October 1, various theaters. For complete information, see www.nymf.org.