Question: Which American operatic baritone and actor sung in Porgy and Bess album 

Context paragraphs:
Robert Mosley: Robert Mosley (1927 – April 30, 2002) was an American operatic bass-baritone.  Part of the first generation of African-American opera singers to achieve wide success, he performed in numerous opera productions, recitals, and in concerts from the 1950s through the 1990s.  In 1957 he won the Metropolitan Opera National Council Auditions.  He drew particular acclaim for his portrayal of Porgy in George Gershwin's "Porgy and Bess", a role which he portrayed in the landmark 1976 Houston Grand Opera production, on Broadway, and at the Metropolitan Opera among other opera companies both in the United States and in Europe.

Robert Merrill: Robert Merrill (June 4, 1917 – October 23, 2004) was an American operatic baritone and actor, who was also active in the musical theatre circuit.  He received the National Medal of Arts in 1993.

Porgy and Bess (film): Porgy and Bess is a 1959 American musical film directed by Otto Preminger.  It is based on the 1935 opera "Porgy and Bess" by George Gershwin, DuBose Heyward, and Ira Gershwin, which is in turn based on Heyward's 1925 novel "Porgy", as well as Heyward's subsequent 1927 non-musical stage adaptation, co-written with his wife Dorothy.  The screenplay for the film, which turned the operatic recitatives into spoken dialogue, was very closely based on the opera and was written by N. Richard Nash.

Bruce Hubbard: Bruce Hubbard (1952 − 1991) was an American operatic baritone.  A Drama Desk and Laurence Olivier Award nominee for Best Actor, he performed on Broadway, the Metropolitan Opera, BBC television, in concert and made several recordings.  He is most famous for appearing as Joe in "Show Boat", and as Jake, as well as Porgy, in "Porgy and Bess" on Broadway, the West End, and in several major opera houses and regional theatres.  He graduated from the Indiana University School of Music.

Marquita Lister: Marquita Lister (born 24 April 1961) is an American operatic soprano.  She has sung with major companies in the U.S. and abroad, specializing in the lirico-spinto repertoire.  Lister is considered one of the leading interpreters of Bess in "Porgy and Bess", having performed the role hundreds of times in companies across the globe, and she is also renowned for her portrayals of Aida and Salome, two signature roles.

Bess, You Is My Woman Now: "Bess, You Is My Woman Now" is a duet with music by George Gershwin and lyrics by Ira Gershwin.  This song comes from the Gershwins' opera "Porgy and Bess" (1935) where it is sung by the main character Porgy and his beloved Bess.  They express their love for each other and say that they now belong together.

Zheng Zhou: Zheng Zhou is an American operatic baritone who has sung at many of the world's finest opera houses.  His opera credits include performances with the Metropolitan Opera, San Francisco Opera, New York City Opera, Tulsa Opera, Opera Illinois, Teatro Nacional de São Carlos, Teatro Real, the Philippine Opera Company, and Vancouver Opera to name just a few.  His concert work includes performances with the American Composers' Orchestra, San Francisco Symphony, New Mexico Symphony Orchestra, Boston Symphony Orchestra, Baltimore Symphony, Jacksonville Symphony, Colorado Symphony, the China National Symphony, and the Shanghai Symphony among many others.

Marvis Martin: Marvis Lynn Martin is an American operatic soprano, best known for her concert performances and recitals, including her renditions of Joseph Canteloube's "Songs from the Auvergne", and of Bess in Bobby McFerrin's touring concert version of "Porgy and Bess".

Warren Coleman: Warren Coleman (24 August 1900 – 13 January 1968 in West Tisbury, Martha's Vineyard) was an American operatic baritone.  He created the roles of Crown in Gershwin's "Porgy and Bess" and the role of John Kumalo in Weill's "Lost in the Stars", in the premiere of both shows on Broadway.

Porgy and Bess (1950 album): This album is a 1950 recording of selections from George Gershwin's opera Porgy and Bess, sung by the noted opera stars Robert Merrill and Risë Stevens.  The album featured no black singers at all, even though the opera was written for a mostly African-American cast (the whites in the opera speak, but do not sing).  It was recorded by RCA Victor on September 12 and September 13, 1950.  The album was originally released on one twelve-inch 33⁄ rpm LP with the catalog number LM 1124.

Supporting paragraphs: Porgy and Bess (1950 album) Robert Merrill
Answer: Robert Merrill