Sister Cristina won the "Voice of Italy" competition June 5 in Milan, singing Top 40 hits, and was signed to a record deal by Universal.
The musical, based on the 1992 movie of the same title, opens at the Brancaccio Theatre in Rome. She said in an interview that she hopes her appearance will be blessed by the Pope.
It's not her first stage role. Eight years ago, when she was 19, she played the founder of a branch of the Ursuline nuns in a musical about the order to which she now belongs.
Proceeds from her singing career go to charities in Italy and in Brazil, where she worked for two years.
A clip of her performance on "Voice of Italy" appears below:
Sister Act is written by multi-Emmy Award winners Cheri and Bill Steinkellner, with additional book material by Tony and Olivier Award nominee Douglas Carter Beane. The score was composed by Oscar winner Alan Menken with lyrics by Glenn Slater.
The plot is described thus: "When disco diva Deloris Van Cartier witnesses a murder, she is put in protective custody in one place the cops are sure she won't be a found: a convent. Disguised as a nun, she finds herself at odds with both the rigid lifestyle and the uptight Mother Superior. Using her unique talents to inspire the choir, Deloris breathes new life into the church, but in doing so blows her cover. Soon it is nun-on-the-run time but she finds salvation in the heavenly power of her newly found sisterhood."
Among others, she helps bring convent-mate Sister Mary Robert out of the shell.