Up the Sandbox was the first film that Streisand made with her then new production company, "First Artists," which she formed with Dustin Hoffman, Steve McQueen, Paul Newman, and Sidney Poitier. Star Barbra Streisand said of this film around the time the movie was made and released: "This story interests me more than anything else I've ever done. It's a departure from the romances, slapstick comedies, and musicals I have worked on up till now". Reportedly, a number of alternate endings were written and filmed before settling on the one in the released version. One of the unused endings was to leave the viewer not entirely sure that what they'd seen was reality or yet another fantasy sequence. Director Irvin Kershner told Streisand biographer James Spada that he wasn't happy with the shooting script, but was advised not to express his dissatisfaction to Streisand, who might walk-off the picture. Several days into filming, Streisand went to Kershner and asked him why they were having so much trouble, and he told her they had started shooting with a weak script. Kershner said, "Your people warned me not to tell you," to which Streisand laughed, "That's ridiculous! If a script isn't good enough, let's work to improve it." Streisand is only heard singing in the film briefly, in a comical duet with her daughter at bedtime. A song for the film, "If I Close My Eyes," was released as a single, but was not used in the film.