[8] Buths's festival co-director Richard Strauss was impressed enough by what he heard that, at a post-concert banquet, he said: I drink to the success and welfare of the first English progressive musician, Meister Elgar.
[9] In the meantime, Buths had conducted the European and German premiere of the Enigma Variations, in Düsseldorf on 7 February 1901.
As a pianist, he was the soloist in the first performance of Delius's Piano Concerto in C minor, at Elberfeld in 1904, conducted by Hans Haym (1860–1921).
[14] He conducted Gustav Mahler's Resurrection Symphony in Düsseldorf on 3 April 1903,[15] in preparation for which he engaged in correspondence with the composer, who advised him to ensure a significant pause between the first and second movements.
[16] Buths nevertheless inserted the long pause (five minutes) between the fourth and fifth movements, for which Mahler congratulated him on his insight and sensitivity, and courage in daring to ignore the composer's wishes.
[17] In 1906, along with Ossip Gabrilowitsch, Alban Berg and Oskar Fried, he attended the rehearsals for the premiere of Mahler's Sixth Symphony in Essen and they all dined with the composer.