Love Me Tonight (1932) A early musical featuring the music of Rodgers and Hart, directed by Rouben Mamoulian is not as full blown as musicals would eventually become. Maurice Chevalier is a lowly tailor who falls for a well stationed princess. When the tailor presses an aristocrat to pay his unpaid bills, the deadbeat introduces the tailor to princess's family as a baron. Not the first movie about love blossoming from different sides of the track, or maybe it really is. Chevalier's performance of "Mimi" may have served as inspiration for a Flight of the Conchords song.
Trouble in Paradise (1932) Ernst Lubitsch directs a story of thieves and pickpockets that become part of a love triangle with a mark.
Inclusion of these titles in "The Book" is, in my humble opinion, a coin toss. It's back story concerning the censorship of risque scenes and dialog in light of today's culture is probably the most interesting aspect.