Judith Blegen, a successful lyric coloratura soprano, was known for singing the high-flying, sparkling roles, like Musetta in La bohème, Sophie in Der Rosenkavalier, and Blondchen in Die Entführung aus dem Serail; she also excelled in oratorio and recital repertory. Her career began in 1963, while still a student at the Curtis Institute in Philadelphia, when she was engaged to perform at Gian Carlo Menotti's Spoleto festival. (The composer would create the role of Emily in his opera Help! Help! The Globolinks! for Blegen in 1969). Blegen spent the next several years cultivating an operatic career in Europe, first in Nuremburg, and then in Vienna and Salzburg. During that time she established herself as a top-notch performer in a wide variety of roles, including Zerbinetta (Ariadne auf Naxos), Susanna (The Marriage of Figaro), Olympia (The Tales of Hoffmann), Rosina (The Barber of Seville), and Papagena (The Magic Flute).
From 1969 on, Blegen sang frequently at New York's Metropolitan Opera, where she added Zerlina (Don Giovanni), Adele (Die Fledermaus), Sophie, Blondchen, and Gilda (Rigoletto) to her repertory, as well as many other leading roles. Covent Garden engaged her for a production of Così fan tutte in 1975, and in 1977 she made her debut at the Paris Opera, further cementing her international reputation.
The best examples of Blegen's singing preserved on record include an Exultate Jubilate of Mozart and Haydn's Lord Nelson Mass on Sony, a La bohème on RCA with Plácido Domingo and Sherill Milnes, and Orff's Carmina Burana with Michael Tilson Thomas on CBS.