How do you find a good show in the New York Musical Theater Festival?Its fourth season, which runs through Oct. 7, boasts 34 new tuners, and most of them seduce auds with intriguing concepts, catchy titles and established stage performers. However, anyone with festival experience knows those kinds of promises are usually broken. Ultimately, auds just have to buy their $20 tickets and hope for the best. As usual with NYMF, buzz isn’t narrowing the field. Internet chatter hasn’t anointed a clear favorite, and anecdotal research suggests most shows are selling well. It may be several weeks before we know if the fest has produced its next “Altar Boyz.” But if nothing else, it has demonstrated that writers haven’t run out of ideas. Among the impressively diverse offerings are “Sherlock Holmes (The Early Years),” a romantic comedy about the classic detective; “Maccabeat!” a Hanukkah musical that references everything from boy bands to doo-wop; and “Virtuosa,” a biotuner about composer Clara Schumann that features only one actress and one pianist. One of the fest’s most inventive musicals is also one of its most successful. “Going Down Swingin’ ” transplants the story of “Don Giovanni” to a 1950s radio station studio, where the onslaught of television and the threat of younger men is making caddish host Dean Newhouse (Christopher Shyer) fear for his future. Composer Peter Hilliard and lyricist-librettist Matt Boresi hurl several conceits at the audience, but all of them land with graceful wit. The production unfolds over a day of rehearsals for various radio shows, and the central plot emerges as Newhouse bickers with his co-stars during breaks. Shuttling between parody radio programs and the darker story of Newhouse’s immorality, Boresi ably balances the light with the sinister. The show could use another rewrite, particularly for its overcomplicated ending, but the script’s journey to smart, satisfying entertainment feels almost complete. Highlights include Marla Schaffel as Dean’s tough-dame ex-girlfriend; and Tom Deckman as an actor in his late 20s, still playing the dorky teenager in a wholesome comedy. The disconnection between his “aw-shucks” voice and “this sucks” face is charming. As star of “The Yellow Wood,” Jason Tam is charming, too, though his energy gets wasted on weak material. Written by Michelle Elliott and Danny Larsen — and directed by actor B.D. Wong — this ambitious drama follows Adam, a Korean teenager trying to find his path in life. The score blends Korean influences, teen pop and, of all things, videogame sounds. The resulting hodgepodge is interesting but shapeless, just like the book. Because they never decide which issue is most important to their story — be it Adam’s resentment of his Korean heritage, his quest to get off Ritalin, his fear of his own imagination or his improbable run for class president — Elliott and Larsen shortchange them all. “Unlock’d” could also use some editing. Based on Alexander Pope’s mock-heroic poem “The Rape of the Lock,” Sam Carner and Derek Gregor’s comic tuner follows a silly damsel who loves her hair — each strand is individually named — more than any of her suitors. Both Carner’s words and Gregor’s music have hints of inspiration, but they overwork their best moments. A trio of feisty gnomes may have a cute theme song, for example, but by the fourth time they croon it, it’s tedious. Trimmed of its fat, the show would be a much tastier trifle. For a lesson on how to deliver a joke, Carner and Gregor can turn to “I See London, I See France (The Underwear Musical).” Despite a rushed, unconvincing conclusion, it delivers a feel-good feminist message with catchy pop hooks and a plot that hums like an engine. Thanks to writers Jeremy Desmon and Vid Guerrerio and star Sandy Rustin, we’re treated to airy fun as ad exec Gina realizes her life as a “smart girl” has left her 35 and lonely. Even more troubling, she keeps seeing a trio of perky bimbos (all named Bunny) who sing about the sex she’s not having, and every time she meets with an underwear model (Nicholas Ardell), she can only see him in his skivvies. We see Ardell in his underwear, too, which provides us with eye candy and helps us empathize with Gina’s plight. Flustered and hopeful, she becomes an endearing heroine who can legitimately anchor a musical. The writers employ enough social commentary to elevate the show above fluff, but they deserve the most praise for freshening up a hoary girl-power narrative. If it ever does break away from the NYMF pack, “I See London, I See France” will likely be a crowdpleaser.