Ben, diffident and awkward, is meant to be a jazz trumpeter but wastes his time drinking in Manhattan bars and trying to pick up girls with two fellow-idlers, Dennis and Tom. He is supported by his brother Hugh (the sibling with the most African-American skin-tone characteristics), who is supposed to be a jazz singer but is unable to find much work because of his old-fashioned style. Hugh's career is managed by Rupert. Ben and Hugh live with their fair-skinned, younger sister Lelia, who intends to be a writer. Initially, she is under the wing of an older boyfriend and intellectual, David. At a party, she abandons him for the younger Tony, who professes his love and takes her virginity. She has been disappointed by Tony, and the first act of sex but they continue dating. Seeing her home, he is shocked to find that her family are black and is kicked out by Hugh, who does not want his sister going with a perceived bigot. Lelia is paired with a pleasant black man, also called David, who is shocked at the modern and independent ways she has acquired. Ben, after getting beaten up for trying to drunkenly muscle in on some girls in a bar, comes back to the apartment. Hugh gets into an argument over bookings and his manager confesses he wants to split up. Hugh convinces Rupert that they should remain partners and swears to be more flexible.
As Lelia and David head out for another date, Tony arrives at the door looking for her. He is disappointed to see her already dating another man, and she walks past him, but Hugh also arrives and they get into an argument over Lelia. A beaten up and more sanguine Ben becomes the arbiter and calms the situation down. Hugh discovers he has a good booking in Chicago and leaves. Ben is the last sibling to leave the apartment and heads down the street. Destination unknown.
