The Spanish-born Swiss soprano, Hedy [Hedi] Graf, studied at the Conservatory of Zürich from 1949 to 1952, and with the singing teacher Regine Salomon in Zürich. She completed her studies with Roy Henderson in London (1952, 1956) and with the well-known soprano and pedagogue Sylvia Gaehwiller in Zürich.
Since 1955 Hedy Graf was a prominent concert singer in Switzerland, and was active also in Germany. She sang an extremely broad repertoire, which included parts in oratorios and sacred vocal works of all kinds, and its high points in the great works of J.S. Bach, George Frideric Handel, Haydn, Mozart, L.v. Beethoven, Bruckner. She performed works from the Baroque repertoire, as well as works of contemporary composers (O. Schoeck, Willy Burkhard, Frank Martin, Paul Hindemith, Igor Stravinsky, Arnold Schoenberg). She participated in some premieres of modern works, thus in 1966 in Zürich in the oratorio Jeremia by E. Hess, in 1965 in Zürich and Basel in Cantico di frate brine di San Francesco d'Assisi by Rudolf Moser, in 1977 in Radio Zürich in Tenebrae by M. Schlumpf. Her repertoire of Lieder and Arias encompassed all periods of music history. Her concert appearances were not only limited to Switzerland and Germany. She appeared also in Antwerp, Jerusalem, Tel Aviv, in Scheveningen, Vienna and Strasbourg.
Hedy Graf, who was married with the violist Werner Esser, worked as singing teacher at the Canton School in Küsnacht (Canton Zürich) and in Zürich. She was resident of Benken (Canton Basel-Land).
Recordings: Erato (Bach Cantatas), Cantate (Messiah by G.F. Handel, Christmas Cantatas of the Baroque period), Pallas (Mozarts Requiem).