Question: William Youmans is most famous for his work in a musical who's lyrics and music written by whom?

Context paragraphs:
Titanic (musical): Titanic is a musical with music and lyrics by Maury Yeston and a book by Peter Stone that opened on Broadway in 1997.  It won five Tony Awards including the award for Best Musical.  "Titanic" is set on the ocean liner RMS "Titanic" which sank on its maiden voyage on April 15, 1912.

Flying Down to Rio: Flying Down to Rio is a 1933 American pre-Code RKO musical film noted for being the first screen pairing of Fred Astaire and Ginger Rogers, although Dolores del Río and Gene Raymond received top billing and the leading roles.  Among the featured players Franklin Pangborn and Eric Blore are notable.  The songs in the film were written by Vincent Youmans (music) and Gus Kahn and Edward Eliscu (lyrics), with musical direction and additional music by Max Steiner.  This is the only film in which screen veteran Rogers was billed above famed Broadway dancer Astaire.

Two Little Girls in Blue: Two Little Girls in Blue is a musical theatre work composed by Paul Lannin and Vincent Youmans, with lyrics by Ira Gershwin (under the pseudonym "Arthur Francis") and a libretto by Fred Jackson.  The musical premiered at the George M. Cohan's Theatre on Broadway on May 3, 1921.

William Youmans: William Youmans is an American Broadway, film and television actor and singer, best known for originating the roles of John Jacob Astor in "Titanic: the Musical", and Doctor Dillamond in "Wicked".

Wildflower (musical): Wildflower or The Wildflower (as styled on the sheet music), is a musical in three acts with book and lyrics by Otto Harbach and Oscar Hammerstein II and music by Herbert Stothart and Vincent Youmans.  The plot concerns a pretty Italian farmgirl, Nina, who has a fiery temper.  She stands to inherit a fortune provided that she can keep her temper under control for six months.  If she fails, the money goes to her cousin Bianca, who tries to provoke her.  She manages to do it, and gets the money, as well as her man, Guido.  Several of the songs were published, among which "Bambalina" and the title song were the most popular.  The musical proved to be Day's last Broadway show before moving to London.

Sometimes I'm Happy (Sometimes I'm Blue): "Sometimes I'm Happy (Sometimes I'm Blue)" is a popular song.  The music was written by Vincent Youmans, the lyrics by Irving Caesar.  The song was published in 1927 and introduced in the Broadway musical "Hit the Deck," starring Stanley Holloway, and opened in April 1927.

Tea for Two (song): "Tea for Two" is a song from the 1925 musical "No, No, Nanette" with music by Vincent Youmans and lyrics by Irving Caesar.  It is a duet sung by Nanette and Tom (Louise Groody and Jack Barker) in Act II as they imagine their future.  It was also sung by Doris Day and Gordon MacRae in the 1950 musical film, "Tea for Two".

Mary Jane McKane: Mary Jane McKane is a musical comedy in three acts with book and lyrics by William Carey Duncan and Oscar Hammerstein, II and music by Herbert Stothart and Vincent Youmans.  The show was produced by Arthur Hammerstein at the Imperial Theatre, and opened December 25, 1923.

Without a Song: "Without a Song" is a popular song with music by Vincent Youmans and lyrics by Billy Rose and Edward Eliscu, published in 1929.  It was included in the musical play, "Great Day".  The play only ran for 36 performances but contained two songs which became famous, "Without a Song" and "Great Day".

Song of the West: Song of the West (1930) is an American Pre-Code musical operetta film produced by Warner Bros., and photographed entirely in Technicolor.  It was based on the 1928 Broadway musical "Rainbow" by Vincent Youmans (music), Oscar Hammerstein II (lyrics) and Laurence Stallings (book).  It starred John Boles, Joe E. Brown and Vivienne Segal, and was the first all-color all-talking feature to be filmed entirely outdoors.

Supporting paragraphs: William Youmans Titanic (musical)
Answer: Maury Yeston