Question: The 1927 musical "Show Boat" Features a character, Steve, who acts as a substititute for what feature of Ancient Greek plays, typically consisting of 12-50 players?

Context paragraphs:
Greek chorus: A Greek chorus, or simply chorus (Greek: χορός , "khoros") in the context of Ancient Greek tragedy, comedy, satyr plays, and modern works inspired by them, is a homogeneous, non-individualised group of performers, who comment with a collective voice on the dramatic action.  The chorus consisted of between 12 and 50 players, who variously danced, sang or spoke their lines in unison and sometimes wore masks.

Ol' Man River: "Ol' Man River" (music by Jerome Kern, lyrics by Oscar Hammerstein II) is a show tune from the 1927 musical "Show Boat" that contrasts the struggles and hardships of African Americans with the endless, uncaring flow of the Mississippi River.  It is sung from the point of view of a black stevedore on a showboat, and is the most famous song from the show.  The song is meant to be performed in a slow tempo, it is sung complete once in the musical's lengthy first scene by the stevedore "Joe" who travels with the boat, and, in the stage version, is heard four more times in brief reprises. Joe serves as a sort of musical one-man Greek chorus, and the song, when reprised, comments on the action, as if saying, "This has happened, but the river keeps rolling on anyway."

Show Boat: Show Boat is a musical in two acts, with music by Jerome Kern and book and lyrics by Oscar Hammerstein II, based on Edna Ferber's best-selling novel of the same name.  The musical follows the lives of the performers, stagehands and dock workers on the "Cotton Blossom", a Mississippi River show boat, over 40 years from 1887 to 1927.  Its themes include racial prejudice and tragic, enduring love.  The musical contributed such classic songs as "Ol' Man River", "Make Believe", and "Can't Help Lovin' Dat Man".

You Are Love: You Are Love is a song by Jerome Kern and Oscar Hammerstein II from their classic 1927 musical play "Show Boat".  It is sung twice in the show - first, by Magnolia Hawks, the heroine, and riverboat gambler Gaylord Ravenal when they agree to marry near the end of Act I, and again in the penultimate scene of Act II by Ravenal when he returns to Magnolia after having deserted her for twenty-three years.

Can't Help Lovin' Dat Man: "Can't Help Lovin' Dat Man" with music by Jerome Kern, and lyrics by Oscar Hammerstein II, is one of the most famous songs from their classic 1927 musical play "Show Boat", adapted from Edna Ferber's novel.

Gaylord Ravenal: Gaylord Ravenal is the leading male character in Edna Ferber's novel "Show Boat", in the famous Jerome Kern-Oscar Hammerstein II musical play of the same name based on the novel, and in the films made from it.  He is a compulsive riverboat gambler, and he becomes leading man of the show boat Cotton Blossom at the same time that Magnolia Hawks, the captain's daughter, becomes the leading lady.  In the novel, this happens after several of the company's leading men and ladies have left, including the illegally married mulatto Julie Dozier (to whom Magnolia was especially close) and her white husband Steve Baker.  In the musical, Magnolia and Ravenal become the leading players on the boat immediately after Julie and Steve are forced to leave the show, and not years later.

Mis'ry's Comin' Aroun: Mis'ry's Comin' Aroun is a once-neglected song from the 1927 musical "Show Boat" by Jerome Kern and Oscar Hammerstein II.  It was cut from the production during the Washington D.C. tryout on the orders of producer Florenz Ziegfeld, supposedly because it was one of the factors that made the show too long (it ran four-and-a-half hours when it premiered).  However, musical theatre historian Miles Kreuger and conductor John McGlinn, also suggest that it was the dark, dramatic tone of the piece that most concerned Ziegfeld.  Kern was reportedly so incensed by the deletion of "Mis'ry's Comin' Aroun" that he made it the principal motif of Show Boat's original overture and asked orchestrator Robert Russell Bennett to work sections of it into the background music as well, where it is now played by the orchestra during some of the dialogue scenes involving the mixed race actress Julie La Verne.

Howard Marsh: Howard Marsh (1888 - 1969) was a leading Broadway tenor of the 1920s.  He created the role of Baron Franz Schober (not Franz Schubert) in Sigmund Romberg's operetta drawn from Schubert's life and music, "Blossom Time", in 1921, and that of Prince Karl Franz in the original 1924 production of Sigmund Romberg's operetta "The Student Prince".  Marsh also played Gaylord Ravenal in the original 1927 Broadway production of Jerome Kern and Oscar Hammerstein II's "Show Boat".  He played Ravenal only in the original production of "Show Boat", not in any of the revivals, and never appeared in films or on television.  Despite appearing in three musical theatre smash hits over a span of seven years, Marsh made his last appearance in a new show in 1930, "The Well of Romance", opposite his "Show Boat" co-star, Norma Terris.  After that, he appeared in major roles on Broadway in 1930's revivals of some Gilbert and Sullivan operettas.  He made no recordings of the songs that he sang either in "The Student Prince" or "Show Boat", but he did record some of those Gilbert and Sullivan selections.  None of his recordings has appeared on CD as yet.  Marsh was born August 16, 1888 in Bluffton, Indiana.

Bill (song): "Bill" is a song heard in Act II of Kern and Hammerstein's classic 1927 musical "Show Boat".  The song was written by Kern and P.G. Wodehouse for their 1917 musical "Oh, Lady!  Lady!! " for Vivienne Segal to perform, but withdrawn because it was considered too melancholy for that show.  However, when Kern and Hammerstein were at work on the serious and somewhat tragic "Show Boat", they decided that the song would be perfect for a nightclub scene in the show.  Hammerstein revised Wodehouse's original lyrics somewhat (though he would always give full credit to Wodehouse for the song and take none for himself), and the song was given to real-life nightclub singer Helen Morgan, who portrayed the mulatto Julie in "Show Boat", to sing.

Show Boat (1959 cast album): Show Boat (1959 studio cast album) is a studio recording of the 1927 musical "Show Boat" by Jerome Kern and Oscar Hammerstein II.  The album was recorded in the summer of 1959 at the No.1 studio, Abbey Road, London, and issued by the 'His Master's Voice' label, a subsidiary of EMI, which was run at this time by Norman Newell.  It features a cast that was formed for this recording only; this cast did not perform the show live in any theatre production.

Supporting paragraphs: Ol' Man River Greek chorus
Answer: Greek chorus