Marietta Simpson, known for her deeply expressive, beautiful mezzo-soprano voice, has sung with every major orchestra in the United States and under many of the world's greatest conductors including Kurt Masur, Raymond Leppard, Lorin Maazel, Neville Marriner, Andre Previn, Simon Rattle, James Conon, Helmuth Riling, Patrick Summers, Daniel Barenboim, and Robert Shaw, with whom she made her Carnegie Hall debut. She has also sun with many of the major European orchestras including the Philharmonic orchestras of London, Prague, Berlin, and Vienna. Some of the great operatic stages of the world she has appeared on include La Fenice, La Scala, Glyndebourne, Royal Opera House Covent Garden, and Bregenz, and in the United States with companies such as Houston Grand Opera, LA Opera, New York City Opera, Glimmerglass, Washington National Opera, Augusta Opera, Mobile Opera, and Opera Philadelphia.
Marietta has an extensive discography and has collaborated on several Grammy-nominated recordings. In 2006, she received recognition for her solo role in the Grammy Award-winning recording of William Bolcom's Songs of Innocence and Experience. Her many television appearances include the Emmy Award-winning Stage Fruit and Emmy-nominated Musical Threads: A Musical Journey (produced by WFYI), both with guitarist Dr. Tyron Cooper. Her recently released, highly successful solo CD Crooked Stick: Songs in a Strange Land was filmed by WTIU for national release in spring of 2020.
The recipient of many awards, in 2019 she was selected as a member of the American Academy of Arts and Sciences. She was named Rudy Professor of Music in 2015. In September 2019, Simpson received the IU Bicentennial Medal in recognition of her distinguished contributions to Indiana University.