I'm just curious about allot of compositional techniques, and one of them is the concept of "implying" harmony because it can be useful for determining later harmonic lines for an already written melody or creating a melody that implies a preexisting harmony.
You could also toy with the melody to "imply" other keys (maybe, I'm not sure) and help you modulate more smoothly.
Is it just playing broken chords in the melody with passing notes & neighbor tones or whatever other "non-harmonic" notes / recognizing notes that could work in harmony from the melody ?
How can harmony be implied by melody ?