Other great conductors were also invited to conduct as guests : Hans Richter , Felix von Weingartner , Richard Strauss , Gustav Mahler , Johannes Brahms and Edvard Grieg . This helped to establish the orchestra 's international reputation , and guests Hans Richter , Felix von Weingartner , Richard Strauss , Gustav Mahler , Johannes Brahms and Edvard Grieg conducted the orchestra over the next few years .