[4][5][6] He produced floor shows and theatrical revues both uptown in Harlem and downtown on Broadway's Great White Way.

Harper staged for Broadway Hot Chocolates at the Hudson Theatre and was the premiere producer who opened up the Cotton Club.

[10][better source needed][7] Harper and Osceola Blanks performed in his first big revue, Plantation Days, when it opened at the Lafayette Theatre in Harlem in 1922–23.

From 1923 to 1924, Harper offered the Duke Ellington Orchestra the house band position at the speakeasies Connie's Inn in Harlem and the Kentucky Club in Times Square.

He introduced Louis Armstrong and Cab Calloway to New York show business, and worked with Mae West, Josephine Baker, Lena Horne, Fats Waller and Eubie Blake.

[14][15] Harper was part of the transition team when the Deluxe Cabaret was turned into the Cotton Club, producing two of its first revues during its opening.

Harper died in Harlem, New York, on February 4, 1943, and Adam Clayton Powell Jr. conducted his funeral at the Abyssinian Baptist Church.