they

Considering the singular use of they only violates convention and actually helps communication by providing a singular non-gendered pronoun that doesn't sound like a bad science fiction term, I'd say this is a rule meant to be broken. Language evolves, and there's no reason why the nature of this word can't change if enough people say it should change.

"They," probably arose from the band's full name being a mouthful in conversation. It is greatly in keeping with TMBG's lyrical style to have fans make grammatically playful comments like: "They are so great!"

They (?), pron. pl.; poss. Theirs; obj. Them. [Icel. þeir they, properly nom. pl. masc. of sa, s&umac;, þat, a demonstrative pronoun, akin to the English definite article, AS. s�xc7;, seo, &edh;aet, nom. pl. &edh;a. See That.]

The plural of he, she, or it. They is never used adjectively, but always as a pronoun proper, and sometimes refers to persons without an antecedent expressed.

Jolif and glad they went unto here [their] rest And casten hem [them] full early for to sail. Chaucer.

They of Italy salute you. Heb. xiii. 24.

Blessed are they which do hunger and thirst after righteousness. Matt. v. 6.

They is used indefinitely, as our ancestors used man, and as the French use on; as, they say (French on dit), that is, it is said by persons not specified.

© Webster 1913.