Mignini made her debut in the original Broadway run of
Fiddler on the Roof with
Adrienne Barbeau and
Bette Midler, and later appeared in the show's 50th anniversary tribute at New York's Town Hall. Mignini starred on Broadway and in Los Angeles in
Tintypes, in which she played
Anna Held and was nominated for a
Drama Desk Award.
Time magazine praised Mignini's "seraphic soprano" and her performance was memorialized by caricaturist
Al Hirschfeld. The cast of
Tintypes performed on
The Tony Awards,
The Kennedy Center Honors, recorded an original cast album, and the show was filmed for television. Mignini played Assunta in the 2019
Marisa Tomei-led revival of
Tennessee Williams'
The Rose Tattoo on Broadway. She also appeared on Broadway in
Tricks and
Christopher Durang's
A History of the American Film. Off-Broadway, she appeared in
A.R. Gurney's
Middle Ages,
Christopher Durang's
Sister Mary Ignatius Explains It All For You, and in the
Dorothy Fields' revue
, A Lady Needs a Change. Additional Off-Broadway credits include
The Fantasticks,
I Married Wyatt Earp,
Hereafter,
Master Class as
Maria Callas,
Hard Sell,
Mirandolina,
Legs, and multiple productions at
Ensemble Studio Theatre. Regionally, Mignini appeared in the pre-Broadway tryout of
One Night Stand with
Tony Curtis, Because of Winn-Dixie, Dirt, A String of Pearls, and
Death of a Salesman, and served as music director of a revival of
Kurt Weill's
Happy End in Los Angeles. == Film and television ==