Those Tweedledum and Tweedledee musicals, “The Wild Party” — one scheduled for Broadway, the other for off-Broadway — have started partying.

The only precedent that I know of for two musicals using the same source material in the same season came in 1968, when there were two off-Broadway musicals based on “Twelfth Night.”

But then, at least one had the sense to call itself “Your Own Thing.”

These “Wild Parties” — both based on that jazz-age poem by Joseph Moncure March — have taken on no distinctive nomenclature and are going head-to-head, name-to-name.

First up is the Manhattan Theater Club’s version, which tore into town last week.

It’s a blast. With book, music and lyrics by Andrew Lippa (the upcoming Broadway rival is by John LaChiusa and George C. Wolfe), it tells of Queenie (Julia Murney), a vaudeville performer, and her sadistic lover Burrs (Brian d’Arcy James), a vaudeville clown.

Their once-hot relationship having cooled, they decide to warm it up by throwing a party in their apartment — a crazy bash that turns wild, with booze, coke, sex, jealousy and violence.

Set in 1929, Lippa’s music and unobtrusive yet persuasive lyrics run the gamut from blues to ballad, from jazz to opera, from background hum to foreground blur.

Yet belted out with heartfelt gusto by a talented, energized cast, it works like gangbusters, particularly in the melodramatic second act.

The principals give the show everything it’s worth, ranging from the gutsy and sexy Murney to the forceful, driving James — not to mention a nicely tattered Idina Menzel and a compactly smooth Taye Diggs as the other two corners of the love/lust quadrangle.

The staging, which owes a lot in mood and, at times, even movement to Sam Mendes’ current version of “Cabaret,” is sweetly integrated. You never see the seams between Gabriel Barre’s deft direction and the choreography by the brilliant Mark Dendy, a newcomer to showbiz.

The whole cast is sleazily dazzling, including Alix Korey as a predatory lesbian, Raymond Jaramillo McLeod as a mediocre prizefighter and Jennifer Cody as his doll.

This great ensemble, along with the inventive settings of David Gallo, the stylish yet campy costumes by Martin Pakledinaz, plus the consistently dramatic lighting of Kenneth Posner, all conspire together with Lippa, Barre and Dendy to give this “Wild Party” the mule-like kick of bathroom hooch.

Here is one hell of an imaginative party you won’t want to miss.

Another major theatrical event of the past week was the continuing rehabilitation of Arthur Laurents’ reputation as a playwright, thanks to the revival of his “The Time of the Cuckoo” at the Mitzi E. Newhouse auditorium in Lincoln Center.

Laurents has always been admired for his screenplays and his musicals, especially “West Side Story.” Yet as a playwright, he has — perhaps unjustly — been less highly regarded.

However, with the revival of his “Home of the Brave” a few weeks ago, and now this “Time of the Cuckoo,” I feel a little reassessment is called for.

No, he certainly is not in the same class as Tennessee Williams or Arthur Miller, but apart from those post-war icons, he surely stands way ahead of most of his immediate contemporaries.

I had never previously seen “Cuckoo.” And I suppose I regarded it as just a footnote to the 1965 Rodgers/Sondheim musical based on it, “Do I Hear a Waltz?”

Well, this play of American not-so-innocents abroad in the Venice of the early ’50s now emerges as a zircon-brilliant, if slightly vicious, comedy of manners.

Perhaps overly tough and mildly supercilious in its depiction of the ugly Americans unable to come to terms with good old European hedonism, it is still a wondrously effective portrait of an aging American belle, Leona Samish, who is too fond of the bottle and is looking for true love in the form of a Latin romance.

This, as I recall it, was water downed in David Lean’s movie version, “Summertime,” starring Katharine Hepburn, as it apparently was in the original 1952 Broadway version with Shirley Booth.

Although Laurents sometimes adds the occasional overly flip wisecrack — such as “I was in Firenze for two weeks before I knew it was Florence” — for the most part, the writing proves crisp and honest.

Debra Monk’s foolish and vulgar, yet oddly appealing Leona rightly dominates Nicholas Martin’s brightly unsentimental production, while the play itself, aided and abetted by the eerie accuracy of James Noone’s setting of a Venetian pensione, proves fascinating.

And among the cast, apart from the far-from-nun-like Monk, watch out for Polly Holliday and Tom Aldredge as an elderly couple taking in too much of Europe too fast.

Now, in unfair brevity, are mentions for one smashing direct hit, Ben Jonson’s “The Alchemist” at the CSC Theater, and one near miss, Nilo Cruz’s “Two Sisters and a Piano” at the Joseph Papp Public Theater.

Barry Edelstein’s spot-on modern staging of Jonson’s 17th-century play is as lively as a fox, and Jonson’s brittle yet frantically comic exposé of con men and their dupes is hilariously acted out by one of the best casts in New York.

Dan Castellaneta (the immortal voice of Homer Simpson) and Jeremy Shamos glitter dangerously as the chief villains, but the entire cast is a wild Jonsonian revel, especially Hillel Meltzer as the little tobacconist Abel Drugger, proving as able as the first Drugger I ever saw — Alec Guinness.

Cruz’s “Two Sisters” is also expertly acted, with Paul Calderon and the bouncy Daphne Rubin-Vega both particularly compelling.

Unfortunately, the story of love, irresistible attraction, Cuba and politics, though tautly staged by Loretta Greco and engrossing at the time, is never tied together, leaving the play in the air. Rather like Castro’s Cuba, I suppose.