Just do it! You don't have to apologize to anybody for setting or even composing your own tunes.

If you want to be really conscientious, though, I'd recommend familiarizing yourself with the melodic idiom ("the tradition") hat usually goes with the ballads that are currently on CD, sung by outstanding singers. (Who are they? You probably have some idea already.)

If you write straight from a classical background, the results may be a bit odd. On the other hand, they could be revolutionary! Who can say?

The real point is to express yourself and your feelings about the songs.