In linguistics, synesis (from Greek σύνεσις 'unification, meeting, sense, conscience, insight, realization, mind, reason') is a traditional grammatical/rhetorical term referring to agreement (the change of a word form based on words relating to it) due to meaning.
It is effectively an agreement of words with the sense, instead of the morphosyntactic form, a type of form-meaning mismatch.
One can think of the antecedent of they as an implied plural noun such as musicians.
The term situational agreement is also found, since the same word may take a singular or plural verb depending on the interpretation and intended emphasis of the speaker or writer: Other examples of notional agreement for collective nouns involve some uses of the words team and none.
American style guides give advice, for example, on notional agreement for phrases such as a number of, a lot of, and a total of.