Hello and thank you for your time! My knowledge in music theory is limited, so excuse me. I don't know where to look for the answer.
The goal is simple: harmonize a upper melody with chords stacked below the melody so that it sounds like big band brass hits. I heard in a YouTube video to stack thirds below the melody to achieve that jazz brass sound.
But the problem is that such a generated chord below the Cantus firmus results in a chord with a different root than the note that is actually to be harmonized.
Or is the simplest way just to put inverted seventh chords below the melody line?