Spanish tenor Juan Oncina Espí was born in Barcelona, on 15 April 1921. He spent his youth in Algiers. His father was a good baritone and encouraged him to study singing firstly in Oran and later at the Conservatory of Paris where he studied with Jeanne Camprodón. He was only 17 years old. He returned to Barcelona for his military service and met the famous coloratura soprano Mercedes Capsir who became her teacher and gave him the opportunity to make his debut with Massenet's "Manon" in 1945, at the Teatro Municipal in Gerona, with Capsir in the title role. A tour of different Spanish cities followed, adding to his repertory "La Sonnambula" and "Il Barbiere di Siviglia." He sang in 1946 the role of Paco in "La Vida Breve" by Manuel de Falla, both at the Gran Teatro del Liceo (Barcelona) and Teatro Calderón (Madrid), also with Capsir.

Capsir advised him to continue his studies in Milan with maestro Edoardo Fornarini who formed a repertory adequated to his precious voice of "tenore leggero."

In 1949 Oncina made his debut in Paris singing Paolino in "Il Matrimonio Segreto." The same year he made his Italian debut in the Summer Season at the Castel San Giusto in Trieste, standing in for an ailing Ferruccio Tagliavini as Nemorino in "Elisir d'Amore." Norina was sung by a soprano called Tatiana Menotti¹ (the Musetta in Beniamino Gigli's famous recording of "La Boheme"). She later became his wife.

Juan Oncina had already won reputation as a specialist in Mozart, Rossini and similar composers.

During the season 1948/1949 he sang at the Teatro San Carlo in Naples in the role of Fenton in Verdi's "Falstaff." He became a favourite in the Neapolitan theatre and sang there during 13 seasons. In addition to Fenton he sang there Don Ramiro in "La Cerentola" and Mozart in "Mozart e Salieri" (Rimsky-Korsakov) in 1953/54; Florindo in "Le Donne Curiose" (Wolf-Ferrari) and a recital in 1954/55; Tamino in "Il Flauto Magico" (Mozart) in 1955/6. In april 1956 he traveled with the San Carlo Opera Company to Paris where he sang Almaviva in "Il Barbiere di Siviglia" at the Thèâtre des Champs-Elysèes, again as Almaviva; and the role of George in the new opera "Viví" by Franco Mannino, with soprano Rosanna Carteri in 1957/58; Ferrando in "Cosí fan tutte" (Mozart) in 1957/58; Lindoro in "L’Italiana in Algeria" (Rossini) in 1958/59; Marchetto in "La Grançeola" (Adriano Lualdi) in 1960/61; Maurizio in "Adriana Lecouvreur" in 1962/63; Des Grieux in "Manon" (Massenet) in 1963/64; Roberto in "Maria Stuarda" (Donizetti) in 1968/69; Alfredo in "La Traviata" in 1969/1970 and finally Cavaradossi in "Tosca" (Puccini) in 1971/72.

He also sang for the RAI (Radito Televisione Italiana), in 1949 rhe role of Pedro in "El Retablo de Maese Pedro" (Manuel de Falla), in 1951 the role of Edoardo in "Un giorno di regno" (Verdi); in 1954 the title role in "Werther" (Massenet); in 1955 the role of Don Ramiro in "La Cenerentola" (Rossini); in 1957 the role of Ferrando in "Cosí fan tutte" (Mozart); in 1963 the role of Fernando in "Goyescas" (Enrique Granados); in 1965 the roleof Maurizio in "Adriana Lecouvreur" (Cilea), and finally in 1970 the role of Teseo in "Edipo a Colono" (Antonio Sacchini revised by Gian Francesco Malipiero).

At the famous Teatro dell’Opera di Roma he sang in two seasons, 1954 and 1955, "La Cenerentola" and in 1957 he visited Japan with the company of Opera di Roma, singing in the operas "Falstaff" and "L'Elisir d'amore," as well as in Verdi’s "Messa da Requiem."

From 1952 to 1961 he was engaged at the Glyndebourne Festivals: Don Ramiro in "La Cenerentola" (1952), Comte Ory in "Le Comte Ory" in 1954, with revivals in 1956, 1957, and 1958. The same production was taken in 1958 to Paris, at the Thèâtre Sarah Bernhardt with enormous success.

Other successful peformances included: 1949, as Don Carlos in "L'Osteria Portoghese" by Cherubini at the Maggio Musicale Fiorentino (Florence); 1950, as Rinaldo in "Armida" by Lully ;1956, Almaviva in "Il Barbiere di Siviglia" at Teatro La Fenice (Venice); 1959, as Orombello in "Beatrice di Tenda" by Bellini at the Teatro Massimo (Palermo); and 1965, as Riccardo in "Anna Bolena" by Donizetti.

In addition to the already mentioned places he sang in Switzerland, U.S.A. and Denmark. He also sang in the famous festivals of Aix-en-Provence, Holland and Edinburgh (Adriana Lecouvreur, in 1962). At Strasbourg he sang in "L’Amour pour trois oranges" by Prokofiev. He visited South America only once, singing "L’Italiana in Algeria" at the famous Teatro Colón of Buenos Aires, in 1961.

He did not sing too much in Spain during his career. In 1950 he sang "Il Barbiere di Siviglia" at the Teatro Campoamor, in Oviedo. He sang at the Liceo in Barcelona in 1953 (Werther); 1961/62 (Don Giovanni); 1963/4 (Rigoletto) and 1969/1970 (Mefistofele).

During the 60’s there was a change in his voice and, of course, in his repertory: Adriana Lecouvreur, Mefistofele, Roberto Devereux, Un Ballo in Maschera, Luisa Miller, La Forza del Destino, Don Carlo and Carmen, among many others.

Oncina was very successful in Vienna (he sang there for ten seasons) and Hamburg during the 70’s. Suffering from goiter after singing in Vienna "Un Ballo in Maschera" in 1977, he retired definitively from singing. In 1985 he returned to live in Barcelona becoming a reputed teacher of singing and also had a hotel in Palma de Mallorca.

He made several recordings, such as "Un Giorno di Regno" and "La Cenerentola" but is better known for his recording of "Don Pasquale," for Decca, in 1965, with Fernando Corena and Graziella Sciutti.