During a contract dispute between Republic Studios and Gene Autry Mr. Siegel brought in a member of a singing group called "The Sons of the Pioneers", whose name was Leonard Slye, and changed his screen name to Roy Rogers.

He also produced The Iron Curtain (1948) and later the Marilyn Monroe musical Gentlemen Prefer Blondes, as well as the star-studded High Society for Metro-Goldwyn-Mayer starring Frank Sinatra, Grace Kelly, Bing Crosby, and Louis Armstrong.

[6] However Ben Thau got the job and Siegel remained a producer, making Les Girls, Man on Fire, Merry Andrew, and Some Came Running.

His key producers at the studio around this time were John Houseman, Arthur Freed, Joseph Pasternak, Pandro Berman and Laurence Weingarten.

[16] The following month Siegel announced MGM was "in its strongest position in history from the standpoint of big scale product" adding "it has taken us several years to attain this momentum.

Filming was taking place on Mutiny on the Bounty, How the West Was Won, The Wonderful World of the Brothers Grimm, Sweet Bird of Youth, A Very Private Affair, I Thank a Fool, All Fall Down and The Horizontal Lieutenant.

Filming was about to start on Billy Rose's Jumbo, Two Weeks in Another Town, and Swordsman of Siena, and projects planned (not all of which were ultimately filmed) included Boys' Night Out, Damon and Pythias, Seven Seas to Calais, Rififi in Tokyo, The Tartars, Period of Adjustment, The Travels of Jaimie McPheeters (which became a TV series), The Rise and Fall of the Third Reich (eventually adapted for TV), The Prize, The Courtship of Eddie's Father, George Bradshaw's It's Only a Paper Moon, Over the Rainbow, Guns in the Afternoon (released as Ride the High Country), Peter Matthiessen's Raditzer, Rona Jaffe's Away from Home, John Steinbeck's Winter of Our Discontent, Franz Werfel's The Forty Days of Musa Dagh and a sequel to Seven Brides for Seven Brothers.