De or het operacomponist?

The correct Dutch article is:

de operacomponist

Rule Words ending in -ist: almost always de. See the rule

How to use operacomponist

the operacomponistde operacomponist
this operacomponistdeze operacomponist
that operacomponistdie operacomponist
our operacomponistonze operacomponist
your operacomponistjouw operacomponist
every operacomponistelke operacomponist
which operacomponist?welke operacomponist?
a big operacomponist / the big operacomponisteen grote operacomponist, de grote operacomponist