Since I only know some very rudimentary terms in music theory, I don't know what it's called when one does the following to create a sort-of interesting sound.
Suppose I'm playing the piano, using my left hand to repeatedly hit the note C as a very simple bass line to give the key of my song (C major). Then I use my right hand to play a melody that fits within the key, but instead of playing notes in the C scale to get a 'cleanly fitting' sound I rather go for playing the melody using the G scale, creating a slightly unusual deviation from what one would expect from a song in the C key.
When I try this out, it creates a sound that I recognize from some songs (for instance the intro song in Disney's Beauty and the Beast uses this kind of 'harmonization' when the villagers greet each other) and the sound feels so natural that I think that the concept of playing the melody in a different scale than the 'expected one', given the key, should be somewhat well known/understood.
Does this kind of 'harmonization' have a name (in the case where we use the dominant (V) scale instead of the scale indicated by the key (I))? And more generally, are other scales than (V) in the melody commonly used to create a 'special feel' to a song?