In 1961 he left Cambridge and started his career as a soloist. He soon became very successful, singing with the English Opera Group. He became well known for singing many roles in the operas of Benjamin Britten. He sang the part of Quint in The Turn of the Screw, including performances in Moscow and Leningrad.
Tear sang solos with many great orchestras under many famous conductors including Leonard Bernstein, Carlo Maria Giulini and Herbert von Karajan. He sang in many famous opera houses in the world. He made over 250 recordings including many cantatas of Johann Sebastian Bach, Benjamin Britten’s Serenade, Nocturne and the War Requiem and Gustav Mahler’s Das Lied von der Erde. He also recorded many Lieder including Schubert’s Die Winterreise.
Robert Tear often conducted in his later years. In 1985 he conducted in Minneapolis in the United States. He conducted many orchestras including the Northern Sinfonia, English Chamber Orchestra, Philharmonia, Royal Liverpool Philharmonic Orchestra, Royal Scottish National Orchestra and the Scottish Chamber Orchestra.
As a singer Tear was especially known for his singing of the music of British composers Benjamin Britten and Tippett. He was the first to sing the role of Dov in Tippett's opera The Knot Garden. He was also well known for his duets with the baritone Benjamin Luxon. They sang many Victorian parlour songs (popular songs) together.
From 1992 to 1994, he was Artistic Director of the Vocal Faculty of the London Royal Schools of Music. He held the Chair of International Singing at the Royal Academy of Music. He was an honorary member of King’s College, Cambridge and was made a CBE in 1984.