Viola Based on the vocalizes of Marco Bordogni, each compilation of etudes is drawn from some of the most musically appealing study material in the vocal repertoire. Carefully transcribed and arranged to be suitable for the study of each instrument, these works represent much more than simply technical studies. A tribute to the great musicianship of this wonderful singer and teacher, Bordogni’s etudes are beautifully expressive in nature and artistically and musically elite.