The use of instrumental vibrato in certain periods of classical music performances has become a highly debated and often fiery topic. The scholars of yesterday had only a few sources with which to gain a better understanding of the definition, mechanics, employment, and prevalent attitudes of those coming before them. This project aims to develop the foundation to a better understanding of instrumental vibrato by compiling primary source material written before 1940 and secondary source material relevant to that period into an annotated bibliography. The source materials in this study were mainly comprised of treatises, tutors, method books, newspaper articles, and dictionaries. The instruments covered in this study included the violin family and relatives (viols, etc...), woodwinds (including recorder), members of the brass family, organ, other keyboard instruments, guitar/banjo/lute, theremin, and prototype
iche instruments (such as player pianos). This project investigated 309 historical documents, finding 258 contained writings about instrumental vibrato. Of those, 157 were presented as bibliographic annotations. The author found no consensus at any time in the history of Western art music between 1550-1940 that vibrato is wholly acceptable or wholly unacceptable.