Suor Angelica (Sister Angelica) is an opera in one act by Giacomo Puccini to an original Italian libretto by Giovacchino Forzano. It is the second opera of the trio of operas known as Il trittico (Triptych). It received its world premiere at the Metropolitan Opera on December 14, 1918.

The opera opens with scenes showing typical aspects of life in the convent — all the sisters sing hymns, the Monitor scolds two lay-sisters, everyone gathers for recreation in the courtyard. The sisters rejoice because, as the Mistress of Novices explains, this is the first of three evenings that occur each year when the setting sun strikes the fountain to turn its water golden. This event causes the sisters to remember a sister who has died, Bianca Rosa. Sister Genevieve suggests they pour some of the golden water onto her tomb.

The nuns then discuss their desires — while the Monitor believes that any desire at all is wrong, Sister Genevieve confesses that she wishes to see lambs again because she used to be a shepherdess when she was a girl, and Sister Dolcina wishes for something good to eat. Sister Angelica claims to have no desires, but as soon as she says so, the nuns begin gossiping — Sister Angelica has lied, because her true desire is to hear from her wealthy, noble family, whom she has not heard from in seven years. The rumors have it that she was sent to the convent in punishment.

Lamberto Gardelli (8 November 1915 – 17 July 1998) was an Italian conductor, particularly associated with the Italian opera repertory, especially the works of Giuseppe Verdi.

Born in Venice, Italy, he studied with Amilcare Zanella and Adriano Ariani at the Liceo Musicale Rossini in Pesaro, and later at the Accademia Nazionale di Santa Cecilia in Rome. He worked as the assistant of Tullio Serafin at the Rome Opera, and made his debut as conductor there with La traviata in 1944.

He became chief conductor at the Stockholm Opera in 1947 and remained until 1955. He was then chief conductor of the Danish Radio Symphony Orchestra from 1955 until 1961, and of the Hungarian State Opera from 1961 until 1966, while making guest appearances at the Glyndebourne Festival, the Royal Opera House in London, the Metropolitan Opera in New York, etc.

Gardelli was considered a specialist in the works of Verdi, and made several recordings of his operas in the 1960s and 1970s, especially many of the neglected early ones with record companies such as Orfeo and Philips. These included Alzira, Attila, Stiffelio, I masnadieri, Ernani, Oberto, Un giorno di regno, Il corsaro, as well as more well-known works such as Nabucco, Macbeth, La traviata, La forza del destino.

Renata Tebaldi (Pesaro, Italy, 1 February 1922 – San Marino, 19 December 2004) was an Italian lirico-spinto soprano popular in the post-war period. Acclaimed as one of the most beloved opera singers of all time, she primarily focused on the verismo roles of the lyric and dramatic repertoires.

Tebaldi was born Renata Ersilia Clotilde Tebaldi in Pesaro, the daughter of a cellist, Teobaldo Tebaldi, and Giuseppina Barbieri, a gifted singer who had wanted a singing career but eventually became a nurse instead. Very soon, the parents split up and Renata, together with her mother, moved to the latter's home town, Langhirano in the Province of Parma.

Stricken with polio at the age of three, Tebaldi was unable to take part in strenuous activities and instead became interested in music. She was a member of the church choir in Langhirano and her mother sent her to piano lessons with Signorina Passani in Parma at the age of thirteen; she worked with boundless diligence, practising four or five hours a day and dreaming of a career as a concert pianist. She also sang everything she heard. Her main source of inspiration was listening to the radio. It was not until her piano teacher took the initiative that Renata was sent to Italo Brancucci, a singing teacher at the conservatory of Parma. She began studying a short time later at the conservatory, taking lessons with Ettore Campogalliani for three years. Renata had to concentrate on scales and voice training for two years before she was allowed to learn the first songs towards the end of her second year of training.

Giulietta Simionato (12 May 1910 – 5 May 2010) was an Italian mezzo-soprano. Her career spanned the period from the 1930s until her retirement in 1966.

Born at Forlì, Romagna, she studied in Rovigo and Padua, and made her operatic debut at Montagnana in 1928. In 1928, she sang in Verdi's "Rigoletto." The first fifteen years of her career were frustrating, she was only given small parts, but she attracted growing attention in the late 1940s, and by the end of her career was recognised as one of the most respected singers of her generation. In 1936, she made her debut at La Scala and appeared there regularly between 1936 and 1966. She made her debut at the Royal Opera House, Covent Garden in 1953, where she likewise appeared regularly between 1963 and 1965.

Simionato made her United States opera debut in 1953 as Charlotte in Jules Massenet's Werther at the San Francisco Opera with Cesare Valletti in the title role. In 1959 she made her debut at the Metropolitan Opera, as Azucena in Il Trovatore, with Carlo Bergonzi, Antonietta Stella, and Leonard Warren. Simionato also appeared at the Edinburgh Festival (1947), the San Francisco Opera (1953), the Teatro Nacional de São Carlos (1954), the Lyric Opera of Chicago (1954–1961), the Vienna State Opera (from 1956), and the Salzburg Festival. In 1957, she sang in Anna Bolena with Maria Callas. In 1961, she withdrew from three performances at the Metropolitan Opera, with Trigeminal Neuralgia.

Giacomo Antonio Domenico Michele Secondo Maria Puccini (Italian pronunciation: [ˈdʒaːkomo putˈtʃiːni]; 22 December 1858 – 29 November 1924) was an Italian composer whose operas, including La bohème, Tosca, Madama Butterfly, and Turandot, are among the most frequently performed in the standard repertoire. Some of his arias, such as "O mio babbino caro" from Gianni Schicchi, "Che gelida manina" from La bohème, and "Nessun dorma" from Turandot, have become part of popular culture.

Described by Encyclopædia Britannica Online as "one of the greatest exponents of operatic realism", he is regarded as one of the last major Italian opera composers. His repertoire is essentially rooted in verismo, or a post-Romantic operatic tradition and literary style. Whilst his work is essentially based on traditional late-19th century Italian opera, his music shows some influences from then-contemporary composers and movements such as Igor Stravinsky and Impressionism. Common themes within his operas include the important role, yet usually tragic end, of his heroines, as well as love; furthermore, there is a strong presence of exoticism in his operas, with several being set in faraway locations.