John the deacon (in Vit. Greg. l. ii. c. 7) expresses the early contempt of the Italians for tramontane singing.
Alpina scilicet corpora vocum suarum tonitruis altisone
perstrepentia, susceptae modulationis dulcedinem proprie non
resultant: quia bibuli gutturis barbara feritas dum inflexionibus
et repercussionibus mitem nititur edere cantilenam, naturali
quodam fragore, quasi plaustra per gradus confuse sonantia,
rigidas voces jactat, etc.
In the time of Charlemagne, the Franks, though with some reluctance, admitted the justice of the reproach. Muratori, Dissert. xxv.