Consistency and change in the musical structure of Moroccan andalusi music studied on recordings from 1932 to 2018

Since the early 20th century, Arab-Moroccan andalusi music, whose standard narrative is that it has remained more or less the same since the expulsion of Muslims from Spain in the 15th century, has been the subject of numerous publications. Alexis Chottin (1891–1975) was one of the first to write down the melodies that had only been passed down orally until then. However, since the notation of andalusi music is still limited to the main voice, the aim of this research project was to make visible for the first time its heterophonic structure -and its modifications -by transcribing early historical recordings from the Congress of Arab Music in Cairo in 1932 in comparison with recordings of the same pieces from 2018.Several field research trips to Morocco from 2014 to 2017 (financed by Pro Helvetia) and the invitation of the Ensemble Harrate from Rabat to Basel in 2018 made it possible to record numerous pieces from the Cairo 1932 repertoire in a comparable instrumentation. On the basis of Chottin's notation of 1931 in combination with audio or video recordings of the same pieces from 1932, (1989) and 2018, the respective performance practice could be analyzed in detail. Thus, on the one hand, the extensive stability of the main voice melody (aṣl/root) could be shown, and on the other hand, the improvisation practice, which has changed over time (in connection with a modified instrumentation and a further developed instrumental technique). This comparison -over a period of 87 years -made it possible to provide answers to the question of the relationship between constancy and change in the musical structure of the andalusi tradit