Borsdorf became professor at the Royal College of Music when it was founded in 1882. He also taught at the Royal Academy of Music. He soon became the best horn player in London. He was playing principal horn in the orchestra which Henry Wood conducted at the very first Promenade Concert in the Queen’s Hall in 1895 (the fourth horn was A.E.Brain, grandfather of Dennis Brain). He was also in the orchestra when Richard Strauss’s "Till Eulenspiegel" was given its first performance in England in 1896 with the composer conducting.