The libretto.
Screenwriter screen/playwright
diva, soprano, alto, bass, tenor, baritone
Opera singers all sing all kinds of operas. There are no special terms for singers of comic operas.
musical, opera maybe?
The libretto.
In opera, the text is written by a librettist.
The text of an opera is called the libretto and the writer is called a librettist.
A person who writes a will is commonly referred to as the "testator."
A Philosopher
A drawer.
proposal
A poetry
publisher
A Singer
A person who writes verses is a poet.
Columnist