Had the international megahit Wicked been produced in the late 70s, we would love to imagine that two-time Tony winners Bernadette Peters and Patti LuPone would have shared the stage as Glinda and Elphaba, respectively. We can almost hear Peters asking, "It's good to see me, isn't it?" or belting out "Popular," and the thought of LuPone literally soaring with "Defying Gravity" is equally thrilling.

 Going back a few decades more, how glorious would Barbara Cook have sounded delivering the stratospheric soprano portions of Stephen Schwartz's score? And, the musical theatre dynamo that was Ethel Merman would surely have been the funniest Elphaba around, and New Yorkers would have undoubtedly heard her rendition of "Defying Gravity" all the way down to Battery Park.

 That Judy Garland never had the chance to star in a Broadway musical is one of the great losses for musical theatre fans. And, what better role to showcase the irrepressible Garland than the irrepressible Auntie Mame in Jerry Herman's Tony-winning musical Mame? We can't decide which would have been more exciting — hearing Garland's throbbing tones exclaiming "It's Today" or that exquisite voice bringing a wealth of emotion to "If He Walked into My Life."

 Just where was Tony winner and Olivier nominee Betty Buckley when the powers that be were looking for someone to succeed Patti LuPone in the original production of Evita? That Buckley never got the chance to play the role of the Argentine actress who rose to become First Lady of her country is one of the major disappointments for fans of notoriously high belters. One can hardly imagine just how amazing Buckley would've sounded belting the high portions of Andrew Lloyd Webber's score ("he supports you, for he loves you, understands you, is one of you"), and we're sure her "Don't Cry for Me Argentina" would have been breathtaking.

 Carol Channing is one of the more unique artists to have emerged in musical theatre history, which may be why she stepped into the role of Dolly Gallagher Levi as often as she did, since there were too few parts to suit her inimitable talents. Had The Drowsy Chaperone come along a few decades earlier, we think Channing, who is blessed with superb comic timing, would have been a real hoot in the title role of the boozy actress/chaperone, and what a delight she would have been singing "As We Stumble Along."

 Most of our favorites actually had the chance to play the ill-fated Norma Desmond in Andrew Lloyd Webber's musical take on Billy Wilder's classic film, but had the musical come along in the 80s, we would have loved to have seen triple-threat Liza Minnelli tackle the role of the former silent-screen star. With her large eyes and expressive features, Minnelli would have been a natural for the demands of the silent screen, and we would have loved to have heard how she would've brought "With One Look" and "As If We Never Said Goodbye" to full, exciting life. And, can't you just picture Minnelli in full Desmond drag insisting, "And, now, Mr. DeMille, I am ready for my close-up!"

 Yes, Harvey Fierstein was near perfection in the role of hausfrau Edna Turnblad in the Tony-winning musical Hairspray, but we can't help but wonder what comic heights Nathan Lane would have reached in the role. And, this is one bit of casting that could still happen!

We know plans are underway for a film remake of Gypsy starring the Academy Award-winning Barbra Streisand as Rose, but hearing that million-dollar voice sing one of the musical theatre's greatest scores live would have been a once-in-a-lifetime experience. In her recent concerts, Streisand did offer a glimpse of the breakdown-in-song that is "Rose's Turn" — guess we'll have to wait for the motion picture to hear the rest of her take on the Jule Styne score.

 While we're at it, we can think of no other actress who didn't get the chance to play Rose on Broadway who should have than Elaine Stritch. We can hardly imagine the volcanic eruption that would have taken place in the musical's penultimate scene between Rose and Gypsy. And, her "Rose's Turn" would have surely been monumental.

It's hard to imagine anyone so wonderfully inhabiting the roles of Edith Bouvier Beale (Act One) and "Little" Edie Beale (Act Two) as Tony winner Christine Ebersole did in both the Off-Broadway and subsequent Broadway production of Grey Gardens. Yet, had the musical come along a few decades earlier, we think five-time Tony winner Angela Lansbury would have been an exquisitely dotty "Little" Edie and an equally enchanting Edith. Just one question: Who would have been Edith to Lansbury's "Little" Edie in the musical's second act?

 We lament the tragic death of pop star Whitney Houston, which also closed the book on a possible Broadway career for the multi-talented artist, but that doesn't stop us from dreaming of Houston starring in a production of the Motown musical Dreamgirls. Although she did cover Effie's anthem, "And I'm Telling You I'm Not Going," Houston  — the Grammy winner whose physical beauty was matched by her phenomenal voice  — would have actually been a perfect Deena Jones. We can almost see and hear Houston leading The Dreams in the musical's title song, "We're your Dreamgirls, boys, we'll make you happy…" That would have made us very happy, indeed.