Where do critics turn to find out more about a work after they have examined it using the art criticism operations?

External Clues

Explanation:

External Clues are the facts and information about the piece of art and the artist, including the name, time and place of creation, and the artistic style it represents. This information can be found on historical sources as well as on other critics' work, and even though it´s likely to be partly already known by the critic should only be considered after an examination. Furthermore, during an examination, only Internal Clues, those found in the work itself, should be considered. Ignoring external clues is necessary to ensure the critic develops an unbiased analysis, and ignore them requires a conscious effort.

the style of music that was composed during the classical era was concerto grosso.