What If...? – Metro-Goldwyn-Mayer (Woody Allen's The Sunshine Boys)

For the job of directing the feature film adaptation of the late great Neil Simon's stage play The Sunshine Boys, which tells the story of two legendary vaudeville comics-turned-bitter rivals — Willy Clark and Al Lewis — who are brought together for a reunion and revival of their famous act, the producers originally looked at another famed comedian: the now-disgraced Woody Allen, who was still a relatively new director at the time and who had previously worked alongside Simon — as well as the likes of Mel Brooks and Larry Gelbart — as a writer on Sid Caesar's Your Show of Shows. While Allen was interested in the material, he wasn't looking to direct, instead desiring to play one of the comics: Al Lewis, specifically. Ultimately, Allen turned down the job and Herbert Ross — who would become a frequent collaborator with Simon — was instead hired to direct, but Allen would later co-star as Lewis in the 1996 made-for-TV re-adaptation of the play. Follow me and ponder the question, "What if...?"

Music: "Make 'Em Laugh" – Nacio Herb Brown and Arthur Freed (Singin' in the Rain)

[alansafier]

You didn't take this far enough. The joke is over as soon as we see the first credits card. And you should have picked music that Woody Allen would have picked instead of what was actually used in the film. A missed opportunity.