Word to describe unimaginative craft?

Solution 1:

There is no single term.

We could talk of perfunctory perfomances for the musician.

For the painter we might talk of an artist (just) going through the motions (Collins), or painting in a mechanical manner.

A poet's work characterized by the rigidity of the poetical form and a poor content could be characterized as an artist given to sterile formalism.

A poet whose workis characterized by the rigidity of the poetical form at the detriment of the content can be said, among other things, to be prisoner of his technique.

Solution 2:

Workmanlike

"competent and skillful but not outstanding or original. an adequate … reporter who turned out workmanlike copy." Merriam Webster