In 1951, while working there she was approached by famed designer Irene Sharaff to assist her with the costumes for Richard Rodgers and Oscar Hammerstein II's The King and I.

[1] It was there she met her companion for the next half century Ruth Mitchell who later would co-produce Broadway shows with Hal Prince.

[2] Klotz won the first of her six Tony Awards for costume design for the 1971 Stephen Sondheim musical Follies.

[5][6] All of the Tony Awards Klotz won were for musicals directed by Hal Prince, with whom she had a long association.

Her sixth award, for the 1994 revival of Show Boat, gave her more Tonys than any previous costume designer.