On 24 March, a few months before his 90th birthday, Rudolf Kelterborn passed away in Basel. On 3 September 2021, the Swiss composer, music educator, teacher and mentor of contemporary music would have celebrated this special birthday.

Rudolf Kelterborn stated, "The ‘content' of my music is determined, on the one hand, by the often almost unbearable tension between the beauties of this world and the unheard-of possibilities of life and, on the other hand, by the fears, terrors and hardships of our time." Tireless progress, irrepressible curiosity, reflection and passionate recreation determined the works of the Swiss doyen.

His work encompasses all genres - from solo pieces to full-length operas. His resumé documents his work in many areas of musical life and his vocation in the comprehensive communication of music. Kelterborn was born in Basel in 1931 and, in addition to his early success as a composer, he also worked as a teacher and professor in Detmold, Karlsruhe, Zurich and Basel, teaching all over the world from the USA to the Far East. Later he became head of the music department at the Swiss Radio DRS, editor-in-chief of the “Schweizerische Musikzeitung”, Director of the Music Academy in Basel and co-founder of the original concert series of the Basler Musik Forum. With these diverse activities, Kelterborn has had a decisive influence on Swiss musical life, not least as a teacher of the composer Andrea Lorenzo Scartazzini.

A constant rethinking of musical structures determined his unceasing creative work as a composer. His compositions are characterised by a richly contrasting, multi-layered, energetic musical language that has an immediate impact and engages the listener.

Numerous concerts of important works had been planned on the occasion of his birthday, including those with the Basel Symphony Orchestra and the Basel Sinfonietta. They will now become sounding obituaries.