Use of the definite article

[Hela]

Good evening Alan,

Would you please tell me if this sentence is correct? If it is, could you please tell me why do we use the definite article before the uncountable noun "art" here?

The main exhibitions at the fair were the art.

Thank you for your help.

[Alan]

It means specifically 'that part of the exhibited material that constituted works of art' (as opposed to other parts, which did not).