The best thing about the terrible state of the American musical is Gerard Alessandrini. If we didn't have musicals that were either horribly pandering or ridiculously pretentious, we might not have Alessandrini's mirth-filled, often hilarious ''Forbidden Broadway," or, as it's called in its latest incarnation, ''Forbidden Broadway: Special Victims Unit."
The Huntington Theatre Company has brought a more site-specific version of the New York musical here, minus goodies like ''Bombay Wet Dreams" modeled after Broadway flops. That hardly means there's any lack of great material.
This show's conceit is that the late Jerry Orbach, himself a onetime Broadway singing star, and some of the ''Law & Order" gang are trying to find out who killed orphan Annie -- and by extension, the American musical. Any number of suspects parade by in the next two hours, from British directors to singers who think they need to belt it out as loud as they can as long as they can.
Not that Alessandrini's cops are interested in making any arrests; his is a take-no-prisoners approach. Not many targets come out with their dignity intact, as Sarah Brightman's trills, Yoko Ono's shrieks, Idina Menzel's blares, and Kathleen Turner's caterwauling (there's some nonmusical merriment, too) all get their deserved amount of birdshot blasted by the four singer-comedians.
Even if all that Alessandrini were doing as writer, creator, and director was sending up these Broadway stars by exaggerating their mannerisms, ''Forbidden Broadway" would still be as jovial a night out as you could find these days.
But the show is much more. Alessandrini is as astute a critic of what ails the contemporary musical as you can find, and when you put his astuteness together with his Tom Lehrer-like talents as a satirist and his wicked -- or ''Wicked"-er -- sense of humor, the combination is unbeatable.
He cuts right to the heart of each of the musicals he trashes. Taking on ''The Light in the Piazza," he simultaneously sends up the pretentiousness of Adam Guettel's music and the dopiness of the story. The singers natter on musically while the brain-damaged blonde is portrayed as literally brain-damaged, without any of the exotica in the musical. Meanwhile, Bob Fosse's cliched sensuality in ''Chicago" and ''Sweet Charity" is skewered with a handful of slinky, silly moves. And isn't it convenient that ''Les Miserables" is in town, the better for Alessandrini to bring back his extended high-note trashing of that musical's wretched sentimentality?
He's also a master of the segue, as a bit on British directors' clueless ransacking of American musicals turns into a pip of a putdown of jukebox musicals. Curly in ''Oklahoma!" finds that Aunt Eller has been replaced by Yoko Ono doing her own ransacking of her late husband's work in ''Lennon":
Imagine all subsidiaries
Give me 6.25% of weekly net
You may say I'm controlling
But I helped John along
Saved him from the Beatles
And their insipid song
You can tell that Alessandrini likes a musical when it's used to satirize other musicals. A song from ''Avenue Q," for example, goes after Brooke Shields in ''Wonderful Town," Norbert Leo Butz in ''Dirty Rotten Scoundrels," and Stephen Schwartz, the composer of ''Wicked."
The four-person Boston cast does right by the material in a variety of roles. Kevin B. McGlynn, in particular, is as gifted a comedian as he is a singer, evidenced by the number he does on both Alfred Molina and Harvey Fierstein in ''Fiddler With No Jew." Janet Dickinson can be shakier than the others. Her Cherry Jones from ''Doubt" bears almost no resemblance to the real thing, though she did elicit one of the bigger oohs from the audience with a slap at the American Repertory Theatre. (Jones is probably the ART's most famous alumna.) Catherine Stornetta's piano accompaniment is solid and unintrusive.
If some of today's composers who insist on working alone -- to the detriment of whichever musical they're working on -- hired Alessandrini to help them out, their work would probably be a whole lot richer.
But then we wouldn't have ''Forbidden Broadway" to bring us such smart and sassy cheer.
Ed Siegel can be reached at firstname.lastname@example.org.