Thomas Rajna was born in Budapest in 1928 and started to play the piano and compose at an early age. He continued his studies at the Franz Liszt Academy of Music and in 1947 left Hungary to settle in London, where he enrolled at the Royal College of Music. He soon appeared at the Proms under such conductors as Giulini, Colin Davis and Pritchard, also becoming a frequent broadcaster for the BBC. In 1963 he was appointed Professor of Piano at the Guildhall School of Music.
He settled in Cape Town in 1970 to take up an appointment at the Faculty of Music of the University of Cape Town, where he became an Associate Professor in Piano in 1989. In January 1981 he was awarded a University Fellowship by UCT and in 1985 he received a Doctorate in Music from UCT in recognition of his body of compositions.
His compositions include two operas, two piano concertos, a harp concerto, a violin concerto, orchestral works, the cantata The Creation - a Negro Sermon, chamber music, songs and works for solo piano.