Currently I am in the process of learning theory to be able to compose rap beats more efficiently and I have one question regarding (minor) scales.
I know the formulas for natural, minor and harmonic scales and also the history of those scales.
However how are these scales being actually used in modern music?
Some time ago I started building songs, say just around the harmonic minor...but the result was really weird, sonically speaking.
So my question is: Can you use multiple scales, or types of scales in one composition?
Say, use c# harmonic minor for the chords and in the same song use the melodic minor just for the melody?
I know that you can basically do anything you want and this is only theory...but still. Is there something of a rule of thumb or guideline as to how to employ those scales?