In 1931, Moyse was teaching in Geneva when the flutist of the Orchestre de la Suisse Romande, Marcel Welsch, committed suicide. Welsch was scheduled to play Bach's "Brandenburg Concerto No. 5" with the orchestra; it was Blanche Honegger who suggested Moyse as a replacement. This was the beginning of the famous Moyse Trio: Marcel-the founder and director-playing flute; Blanche, playing violin and viola; and his son Louis, playing both flute and piano. From its conception in 1934, the Moyse Trio performed and recorded for the next 20 years.