Art required can be expressed in several different ways, depending on the context and the desired tone. Words that convey a sense of necessity might include "essential," "mandatory," or "indispensable." For a more formal tone, one might use "requisite," "pre-requisite," or "obligatory." On the other hand, if the focus is on the creative element of the required art, one could use words like "inspired," "innovative," or "original." Alternatively, for a more practical approach, one might use "functional," "usable," or "applicable." Ultimately, the choice of synonym will depend on the intended message and the audience being addressed.