Dag Achatz is a Swedish virtuoso pianist and composer. His recording for BIS of his own transcription for solo piano of Igor Stravinsky's The Rite of Spring is widely acknowledged to be one of the great recordings of the 20th century. Leonard Bernstein asked him to transcribe his ballet Fancy Free, which Achatz then recorded along with his own transcription of Bernstein's Symphonic Dances from West Side Story.

Born in Stockholm in 1942 of a Swedish mother and a Viennese father, both musicians, he was raised in Switzerland, where he entered the Geneva Conservatory at age of 8. Graduating with honors, he continued his studies with Greta Eriksson in Stockholm, with Alfred Cortot and Guido Agosti in Siena, and with Susanne Roche and Vlado Perlemuter in Paris. In 1960 he claimed victory in the Rudolf Ganz Competition in Lausanne, and in 1964 took first price at the coveted Maria Canals International Music Competition in Barcelona. He was also a prizewinner at the Bavarian Radio Competition in Munich and the Viotti Competition in Vercelli. He has since performed in more than 25 countries and in most major musical centers, including London, Paris, New York, Boston, Berlin, Moscow, Saint Petersburg, Vienna, Tokyo and Beijing.