Busch's 21st birthday was spent en route to Switzerland for a walking and climbing holiday with the Grüters family. He was already friends with two Swiss artists, Max Schulthess and A. H. Pellegrini (who had painted a portrait of Frieda for him), and had long wanted to see their country. He and Frieda were equally captivated by the landscape and the people and, perhaps because they were in love, that first visit inspired a devotion to Switzerland which would never flag. When the weather was good, they spent every possible moment outdoors; when it was bad, they made music in the hotel – fellow guests in their first base, at Les Plans, gave Adolf and Hugo two pictures of the locality in gratitude for renderings of Beethoven and Mozart sonatas. From Les Plans, at the southern end of the Bernese Alps, the party trekked to Trachsellauenen near the Jungfrau peak. They had a musical opus with them which matched the grandeur of their surroundings, as Hugo was studying the new Universal Edition full score of Mahler's Eighth Symphony. When he drew Adolf's attention to a particularly harsh dissonance, the younger man's only comment was that at least it would quickly be passed over in performance. Within little more than a year, this first all-choral symphony would be mounted by Hugo (in Bonn), Fritz (in Aachen) and Steinbach (in Cologne).

While on holiday, Busch was offered the post of first concertmaster of the Vienna Konzertverein Orchestra in succession to Max Grohmann. Both Grümmer and Karl Doktor (who had heard praise of Busch from Reger) had been urging the conductor Ferdinand Löwe to approach Busch as soon as the leader's chair fell vacant; and although Löwe had expressed grave reservations – which it would take him a year to overcome – on account of the candidate's youth, he had finally given in. Only in June, Busch had turned down a similar approach from Stuttgart, but Vienna presented an additional attraction: the orchestral board wanted the string principals to function as a quartet, which would be allowed to tour.