Mayo Methot introduced “More Than You Know” in Great Day, a Broadway musical that opened at the Cosmopolitan Theatre on October 17, 1929, and ran for 36 performances.

Although the musical was a flop, three of the Youmans/Eliscu/Rose songs were not. “More Than You Know,” “Great Day,” and “Without a Song,” became hits within weeks of the show’s closing. A recording of “Great Day,” by Paul Whiteman and His Orchestra, was a number one hit for two weeks, and its flip side, “Without a Song,” which was also to become a jazz standard, climbed the charts to the number six position.

“More Than You Know” was a number nine hit for Ruth Etting and enjoyed success with:

• Ruth Etting (1930, #9)
• Mildred Bailey (1937, #15)
• Perry Como (1946, #19)
• Martika (1989, #18)

Perry Como’s rendition was the B-side to his number one hit “Surrender.”

Great Day was a significant turning point in the life of Harold Arlen. Initially Arlen had earned a singing and acting role (Cokey Joe) in the production, but, when his part was cut, the show’s accompanist and arranger Fletcher Henderson asked Arlen to help him with music for the pit orchestra. When Henderson fell ill, Arlen took over playing piano for the dancers. Between dance numbers Arlen began picking out a song which, with lyricist Ted Koehler, would become “Get Happy” (1929), thus launching one of the best popular songwriting careers of all time.

Soon after the musical’s closing, MGM purchased the rights for Great Day. Despite the show having fizzled, the resulting recordings and sheet music sales had done quite well. Planned for release in 1930, and starring Joan Crawford, the film version of Great Day was given the axe in the middle of pre-production. The exact reason for the shutdown is not clear, but it is rumored that Crawford turned in a bad performance because she was angry with producer Irving Thalberg. Apparently Thalberg had given the lead role for The Divorcée (1930) to his wife, Norma Shearer, who went on to win that year’s Oscar for Best Actress.

The British RKO film Great Day (1945) is not related to the Broadway musical.

In describing Youmans’ “More Than You Know,” Alec Wilder, author of American Popular Song: The Great Innovators, 1900-1950, says, “It ranks among the best of the pop songs…” and that the verse is “nearly a song in itself … clearly written with great care and affection.” Agreeing with Wilder is BBC Radio2 presenter (also, producer, writer, jazz musician, and film critic) Russell Davies:

Not every verse in the Great American Songbook is worth keeping - some of them are too far embedded in the plots of Broadway shows and the like. Others, almost too grippingly written, threaten to take on an independent identity of their own. Listening to the verse of “More Than You Know,” you could easily be persuaded that this was a quite different song called “I’m Growing Fonder of You.”

The prospect was not lost on Fats Waller, who in 1934 published “I’m Growing Fonder of You,” recorded that year by Kate Smith and by Ted Weems and His Orchestra featuring vocalist Fred Waldmar.

Regrettably, jazz vocalists and musicians often omit the verse to “More Than You Know.” It can, however, be heard by the following artists: Sarah Vaughan (How Long Has This Been Going On?), Ella Fitzgerald (Like Someone in Love), Rosemary Clooney (Girl Singer), and Stacey Kent (Close Your Eyes).

With regard to its harmonization, “More Than You Know” is more basic than many of the popular songs of the ‘30s, but, according to Allen Forte in The American Popular Ballad of the Golden Era, 1924-1950 : A Study in Musical Design, the harmony for that era is “very much up-to-date and comparable to Gershwin’s of the same vintage.”