Question: The romance film Breach of Promise starred which woman known to be Noël Coward's muse?

Context articles: Twentieth-Century Blues: The Songs of Noël Coward
London Calling! (musical)
Judy Campbell
Words and Music (musical)
Noël Coward at Las Vegas
I Went to a Marvellous Party
Breach of Promise (film)
Graham Payn
Bitter Sweet (1933 film)
Noël Coward Society

Twentieth-Century Blues: The Songs of Noël Coward is a 1998 Noël Coward tribute album curated by Neil Tennant, who invited prominent artists of the day to reinterpret Noël Coward’s songs for the late 20th century.
London Calling!
 was a musical revue, produced by André Charlot with music and lyrics by Noël Coward, which opened at London's Duke of York's Theatre on 4 September 1923.
 It is famous for being Noël Coward's first publicly produced musical work and for the use of a 3-D stereoscopic shadowgraph as part of its opening act.
 The revue's song "Parisian Pierrot", sung by Gertrude Lawrence, was Coward's first big hit and became one of his signature tunes.
Judy Campbell (born Judith Mary Gamble; 31 May 1916 – 6 June 2004) was an English actress and playwright, widely known to be Noël Coward's muse.
 Her daughter is the actress and singer Jane Birkin, her son the screenwriter and director Andrew Birkin, and among her grandchildren are the actresses Charlotte Gainsbourg and Lou Doillon, the late poet Anno Birkin, the artist David Birkin and the late photographer Kate Barry.
Words and Music is a musical revue with sketches, music, lyrics and direction by Noël Coward.
 The revue introduced the song "Mad About the Boy", which, according to The Noël Coward Society's website, is Coward's most popular song.
 The critics praised the show's sharp satire and verbal cleverness.
Noël Coward at Las Vegas is a 1955 live album by Noël Coward.
"I Went to a Marvellous Party" (sometimes known as "I've Been to a Marvellous Party") is a song with words and music by Noël Coward, written in 1938 and included in the revue, "Set to Music".
 Although a melody exists, the text is most often recited over a piano accompaniment.
 Out of Noël Coward's approximately 300 songs, this piece is one of his most popular, ranking among the top 30 in royalty potential.
Breach of Promise is a 1942 British romance film directed by Harold Huth and starring Clive Brook, Judy Campbell, C.V. France, Marguerite Allan and Percy Walsh.
 A playwright meets a young woman and she soon files a fake breach of promise action against him, hoping to receive a blackmail payment.
 Instead he decides to marry her to teach her a lesson.
Graham Payn (25 April 1918 – 4 November 2005) was a South African-born English actor and singer, also known for being the life partner of the playwright Noël Coward.
 Beginning as a boy soprano, Payn later made a career as a singer and actor in the works of Coward and others.
 After Coward's death, Payn ran the Coward estate for 22 years.
Bitter Sweet is a British musical romance film directed by Herbert Wilcox and released by United Artists in 1933.
 It was the first film adaptation of Noël Coward's 1929 operetta "Bitter Sweet".
 It starred Anna Neagle and Fernand Gravey, with Ivy St. Helier reviving her stage role as Manon.
 It was made at Elstree Studios and was part of a boom in operetta films during the 1930s.
The Noël Coward Society is an international society founded with the agreement of Coward's literary agent and Estate to celebrate the life and work of Sir Noël Coward.