[4] Hallin was appointed Hovsångerska (Royal Court singer) along with Erik Saedén, in 1966, and was awarded the Jussi Björling Scholarship in 1970.

[6] Her opera roles in the 1950s to 1970s included the blind poetess in Karl-Birger Blomdahl's Aniara,[7][8] Anne Trulove in Stravinsky's The Rake's Progress, the title role in Verdi's La traviata, Therese in Lars Johan Werle's Drömmen om Thérèse,[9] and the Queen Mother in Georg Joseph Vogler's Gustaf Adolf och Ebba Brahe.

[10][11] Hallin also performed in Glyndebourne, Florence, Vienna, Hamburg, Moscow, London and Copenhagen, as well as making a tour in the Soviet Union.

The poems were by Nils Ferlin, Harry Martinson, Werner Aspenström and Alf Henrikson – she performed a medley of these in the Drottningholm Palace Church.

[14] Hallin also composed music for Strindberg's works Den Starkare (The Stronger) which was performed in the Rotunda at the Royal Opera in Stockholm in 1991, and Ett drömspel (A Dream Play) in 1992.