Kurt Equiluz was an alto soloist of the Wiener Sängerknaben. At the Austrian State Academy for Music and Art in Vienna he studied music theory, harp and singing with Adolf Vogel. He was a member of the Wiener Akademie Kammerchor from 1945.
In 1957 he appeared in his first solo role at the Wiener Staatsoper as Pedrillo in Mozart’s Die Entführung aus dem Serail and was a member of the house until 1983, performing 69 different roles of the Spieltenor repertory, such as Jaquino in Beethoven's Fidelio or Scaramuccio in Ariadne auf Naxos. He appeared at the Salzburger Festspiele in the premiere of Rolf Liebermann's Penelope (1954), in Frank Martin's Mystère de la Nativité (1960) and in the premiere of Rudolf Wagner-Régeny's Das Bergwerk zu Falun (1961).
Kurt Equiluz became known for his interpretation of Bach's cantatas and oratorios when was engaged in the recordings of Nikolaus Harnoncourt and Gustav Leonhardt covering the complete vocal works with historical instruments. He was the Evangelist in the first recording of Bach's St John Passion on period instruments with the Concentus Musicus Wien in 1965 and in 1970 the Evangelist in the St Matthew Passion. In 1977 he was the Evangelist in a recording of the St Matthew Passion with De Nederlandse Bachvereniging, conducted by Charles de Wolff, with Max van Egmond as the Vox Christi. He recorded the St John Passion, the St Matthew Passion and the Christmas Oratorio also with Michel Corboz. He recorded Bach cantatas also with the Gächinger Kantorei and Helmuth Rilling. With Harnoncourt he recorded works of Claudio Monteverdi, such as his operas L'Orfeo, Il ritorno d'Ulisse in patria, L'incoronazione di Poppea or the Vespro della Beata Vergine 1610. He recorded sacred music of the classical period with the Vienna Choir boys, such as Mozart's Missa solemnis in C minor, K. 139 "Waisenhausmesse", his Coronation Mass, Haydn's Theresienmesse and Schubert's Mass No. 6 in E-flat major, D 950.
Kurt Equiluz started teaching in 1964, was appointed professor of the Musikhochschule of Graz in 1971, and of the Wiener Musikakademie in 1982.Bach: Johannes-Passion, BWV 245
Kurt Equiluz (Evangelist), Max van Egmond, Trebles & Alto Soloists from the Wiener Sängerknaben, Bert van t'Hoff, Jacques Villisech, Wiener Sängerknaben, Chorus Viennensis, Concentus Musicus Wien, conductor Nikolaus Harnoncourt, Teldec 1965
Bach: Matthäus-Passion, BWV 244
Kurt Equiluz (Evangelist), Karl Ridderbusch, soprano soloists of the Wiener Sängerknaben, James Bowman, Tom Sutcliff, Paul Esswood, Nigel Rogers, Michael Schopper, Regensburger Domspatzen, Choir of King's College, Cambridge, Concentus Musicus Wien, Nikolaus Harnoncourt, Teldec 1970 ("Erste Gesamtaufnahme in authentischer Besetzung mit Originalinstrumenten. Aufnahmeort: Wien, Casino Zögernitz, September 1970." - first complete recording in authentic instrumentation with period instruments, Vienna)
Bach: Weihnachtsoratorium, BWV 248
Kurt Equiluz (Evangelist), Barbara Schlick, Carolyn Watkinson, Michel Brodard, Ensemble Vocal de Lausanne, Orchestre de Chambre de Lausanne, conductor Michel Corboz, Erato 1984
Monteverdi: Vespro della Beata Vergine
Margaret Marshall, Felicity Palmer, Philip Langridge, Kurt Equiluz, Thomas Hampson, Arthur Korn, Arnold Schoenberg Chor, Tölzer Knabenchor, Wiener Hofburgkapelle, Choralschola, Concentus Musicus Wien, conductor Nikolaus Harnoncourt, Teldec 1987