Pennies From Heaven

Philandering 1930s sheet music salesman Arthur Parker escapes from his dull life by fantasizing elaborately choreographed musical numbers in which he and the other characters lip-sync to original recording of popular 1930s music.

1978 BBC mini-series created by Dennis Potter - Starring Bob Hoskins,Gemma Craven,and Cheryl Campbell

Later remade as a 1981 film. Starring Steve Martin, Jessica Harper, Bernadette Peters and Christopher Walken

Includes examples of the following tropes:

 * Corrupt the Cutie from meek schoolteacher to hooker in a few months
 * Deconstruction: of Depression-era musicals
 * Downer Ending
 * Nothing but Hits: averted - many of the songs are rather obscure.
 * One-Scene Wonder: Christopher Walken in his "Lets Misbehave" lip-syncing tap-dancing strip-tease.
 * The best part, of course, is Bernadette Peter's reaction.
 * All the other musical numbers were done as set pieces; showing her reactions as an observer is somewhat distracting and takes away from the whole premise of the film.
 * Playing Against Type: Steve Martin played Arthur Parker immediately after playing Navin Johnson in The Jerk
 * Soundtrack Dissonance: basically the central concept of both the movie and the mini-series.