Question: What occupation was shared by Rudolph Polk and Joseph Santley?

Context articles: Harmony Lane
The Loudspeaker
Joseph Santley
Rudolph Polk
She's Got Everything (film)
Brazil (1944 film)
Make Believe Ballroom
Call of the Canyon
Fred Santley
Sleepy Lagoon (film)

Harmony Lane is a 1935 low-budget American film directed by Joseph Santley, based upon the life of Stephen Foster, released by Mascot Pictures.
The Loudspeaker is a 1934 American comedy film directed by Joseph Santley.
Joseph Mansfield Santley (born Joseph Ishmael Mansfield, January 10, 1890 – August 8, 1971) was an American actor, singer, dancer, writer, director, and producer of musical theatrical plays motion pictures and television shows.
 He adopted the stage name of his stepfather, actor Eugene Santley.
Rudolph ("Rudy") Polk (25 November 1892 New York, New York – 16 June 1957 Los Angeles) was an American concert violinist based in New York City during his early years and, during his later years, a Hollywood film director, film industry executive, and artist manager for Jascha Heifetz, Vladimir Horowitz, José Iturbi, and Gregor Piatigorsky.
 In Hollywood, Polk was the assistant musical director to Morris Stoloff at Columbia Pictures.
 After World War II, Polk was musical director for Enterprise Studios.
She's Got Everything is a 1937 American romantic comedy directed by Joseph Santley using a screenplay by Harry Segall and Maxwell Shane, based on a story by Shane and Joseph Hoffman.
 The film stars Gene Raymond and Ann Sothern, with supporting performances by Victor Moore, Helen Broderick, Parkyakarkus (also known by his real name, Harry Einstein), and Billy Gilbert.
 RKO Radio Pictures produced and distributed the picture, which was released on the final day of 1937.
Brazil (also known as Stars and Guitars ) is a 1944 American musical comedy film directed by Joseph Santley and starring Tito Guízar, Virginia Bruce and Edward Everett Horton.
 It is set in Brazil, and involves a composer masquerading as twins, trying to win the hand of an anti-Latin novelist.
Make Believe Ballroom is a 1949 American romantic musical comedy film starring Jerome Courtland, Ruth Warrick, Virginia Welles, and Ron Randell, directed by Joseph Santley and released by Columbia Pictures.
Call of the Canyon is a 1942 American Western film directed by Joseph Santley and starring Gene Autry, Smiley Burnette, the Sons of the Pioneers, and Ruth Terry.
 Based on a story by Maurice Rapf and Olive Cooper, the film is about a singing cowboy who leads a group of cattlemen against the corrupt agent of a large packing company looking to swindle them by undercutting the buying price for beef.
 The film features three songs by Autry and the Sons of the Pioneers, including the classic "Take Me Back to My Boots and Saddle".
Fred Santley (November 20, 1887 – May 14, 1953), also known variously as Freddie Santley, Fredric Santley, Frederick Santley, Frederic Santley, and Fredric M. Santley, was an American character actor of the silent and sound film eras, as well as an actor on the Broadway stage.
 Born in Salt Lake City, Utah on November 20, 1887, as Frederic Mansfield, the son of Laurene Santley, and the stepson of stage actor Eugene Santley.
 He was the brother of filmmaker and stage actor Joseph Santley, both of whom adopted the surname of their stepfather as their stage name.
 He would make his acting debut in a 1907 short, "Pony Express", and would continue to make shorts throughout the 1910s and 1920s.
 In addition, he would appear in numerous plays during this period, including more than a dozen Broadway productions.
Sleepy Lagoon is a 1943 American musical comedy film directed by Joseph Santley and featuring comedian Judy Canova and singer Dennis Day.
 The film was written by Prescott Chaplin, while Frank Gill, Jr. and George Carleton Brown wrote the screenplay.