My TheaterMania colleague Peter Filichia has already taken author Ethan Mordden to task for the title of his new volume of musical theater history, The Happiest Corpse I've Ever Seen (Palgrave Macmillan, $26.95, 320 pp). Mordden's past efforts have borrowed song titles from shows produced during the specific decades under consideration therein (Make Believe, Beautiful Mornin', Coming Up Roses, Open a New Window, One More Kiss); why, for this look at musicals since 1978, was he compelled to quote from "Cabaret," the title song of a musical that opened on Broadway in 1966? But the book's title is misleading beyond that era error: What Mordden describes isn't a happy corpse at all, just a dead one. He's angry at writers' declining intelligence, producers' timidity, and, especially, the outright stupidity of audiences. Yet he's complimentary to many individual titles, suggesting that maybe there's life in the old girl yet. What emerges is not the usual well-organized, perspicacious, witty chronicle of a great American art form but rather, as Mordden admits on page two, "a rant." His insights are still instructive, his writing still lively, his opinions still fun to argue with. This time, though, you may be as baffled as you are enlightened.

Inarguably, it's been a depressing quarter-century for the musical. We all know about skyrocketing production costs. We've grown accustomed to the $100 (or $101.25) ticket -- and, in the case of The Producers, the $480 orchestra seat. We've seen the dimming of star power, the rise and fall of the portentous pop opera, an onslaught of "revisals," and the strange phenomenon of competently written shows with shorter and shorter runs vs. junk that lasts now and forever. What's going on? Mordden ties it all to a larger dumbing-down of popular culture, with rock's literal drowning out of other genres a major miscreant. Not that intelligent rock, or the intelligent rock musical, is impossible: He's admiring of Rent. But in this marketplace, he writes, "Most of the interesting shows fail...What runs is shlock, dance pieces, and a few revivals."

Fair enough. Why, then, does Mordden keep undercutting his own arguments, pursue confused reasoning to praise undeserving titles, and end compelling discussions with indecipherable verbal flourishes? (Side Show's reception, he contends, was "a case of Watership Down Syndrome." Huh?) He's persuasive in his castigation of rock's fake and/or lazy rhyming, and it's easy to share his despair at seeing such mindlessness as Mamma Mia! and Jekyll & Hyde commercially validated. But must he send the reader scampering to the Random House Unabridged to look up words like "parergon" and "adscititiously"? (I'll save you the trouble: The former is an embellishment, the latter more or less means "additionally.") If Mordden so disdains pop opera as a genre, why does he defend The Phantom of the Opera yet virtually ignore the 6,680-performance Les Misérables? If he distrusts corporate theater, why is he so easy on Disney? (Beauty and the Beast gets two glancing mentions, The Lion King is basically bypassed, and Aida is lauded for Bob Crowley's design and the opportunities it afforded people such as Heather Headley.)

Proportion is a problem throughout the book: too much space devoted to this show, not enough to that one. It's reasonable that, while most of Mordden's histories have been apportioned at a decade per volume -- a 1930s history, Sing for Your Supper, is still in the pipeline -- the decline in new work justifies cramming 25 years into one book. And while Mordden's previous works doted overwhelmingly on Broadway, today's changing venues of production legitimately send The Happiest Corpse to Off-Broadway, to London, to the New York City Opera, and to the road (seven pages on the Tom Jones-Harvey Schmidt Colette, which died in Denver; lengthy side trips to their Grover's Corners and to Kander and Ebb's Over and Over). Still, it's puzzling how long Mordden dwells on a title such as Thou Shalt Not when there's no mention at all of, say, Birds of Paradise (1987). And if he was willing to visit the hinterlands, where's The Visit?

One admires his willingness to serve up comprehensive analyses of such one-nighters as Dance a Little Closer and Onward Victoria. Even more valuable are his appreciations of many generally reviled short-run shows: e.g., Roza, Smile, Play On!, Cyrano, Rags, Steel Pier, Raggedy Ann, Jane Eyre, and The Wind in the Willows (he even quotes dialogue from the latter). To Mordden's mind, A Doll's Life was far from the disaster that most critics perceived. Perhaps, he writes, the show "had too much intellectual subject matter to succeed, and too much interesting music and too much Europe." As for the Larry Grossman-Ellen Fitzhugh Paper Moon, which collapsed at Paper Mill, he feels that "Grossman and his partners improved upon" an "unimprovable film." Also notable are his passing nods to the merits of the meretricious: Though Legs Diamond may have been underwritten and overproduced, "a few of the numbers -- 'Now You See Me, Now You Don't' and...'The Man Nobody Could Love' -- could have come right off the cast album of a semi-forgotten fifties hit." True, and nicely put.

But praising the unsung and undersung has its limits -- or should have its limits. A chapter called "Five Special Shows" inflates the merits of Grand Hotel, Titanic, Amour, Sweet Smell of Success, and the Michael John LaChiusa version of The Wild Party way out of proportion. Speaking of LaChiusa: Does anyone else besides Mordden think that Marie Christine will, "by the next generation or so...be in the repertory of every major opera company in the Western world"? (Baby, dream your dream!)

Mordden's blind spots are also evident when he pans good work. After granting that Hairspray is "put together adroitly," he calls it, in three separate places, "stupid junk." Really -- with its Bye Bye Birdie-like satire and its genius for sending audiences out happy? Does Baby, with its spectacular Maltby-Shire score, really amount to nothing more than a show about "six dreary people?" And in a chapter called "Why Can't Susan Smith and Timothy McVeigh Have a Musical? Hitler Has One," Mordden blasts Ragtime for having a terrorist hero. What about Sweeney Todd? Isn't giving voice to the disenfranchised, the misunderstood, and the justifiably angered a strength of the serious musical? Mordden's fury at the sorry overall turn of musical theater often appears to have clouded his good judgment.

Sondheim, of course, comes in for major kudos; so do Hal Prince and a roster of performers who aren't household names but help to uphold a musical theater that relies increasingly on ensembles and less and less on stars. There's also good dish, such as the real story (in a footnote) of why Betty Buckley didn't come into town with Gypsy. Revivals and revisals get their full measure, and there's a touching remembrance of Bill Tynes, whose New Amsterdam Theatre Company paved the way for Encores! and other musicals-in-concert franchises.

To get to the goodies, though, you'll have to wade through unnecessary two-dollar words ("Their dragonnade often reaches apocalyptic utterances, no less worrisome for being comically hyperbolic"), arcane music theory ("...walking between the first and fifth of the tonic, then cutting to the leading tone, and the verse moves from the tonic to the submediant seventh"), needless vulgarity (I won't quote here, but check out the last line of the book), and asides where you can't tell whether or not Mordden is being serious. (Does he really feel that Tim Robbins is "America's great patriot"? I mean, I do -- but does he?) Also, because the endpoint of the survey is about 14 months ago, we get no mention of Wicked, Bounce, Dracula -- or The Boy from Oz, which would certainly puncture his theory that there are no more star vehicles.

Still, what's hardest to countenance is Mordden's non-constructive negativism about stupid writers and stupider audiences -- particularly when it's combined with such effusiveness, frequently unearned, for a large number of shows. Maybe the last quarter-century has been so messy for musicals that the form defies easy characterization; maybe, indeed, we've been spoiled by the clarity of Mordden's arguments in his books on previous eras. His next volume will hark back seven decades to Porter and Rodgers and Hart and late Gershwin -- simpler times, and more hopeful ones for the musical. Perhaps it will be more cohesive than this highly readable yet baleful and off-putting cri de coeur.