Tune

melodia

(melody)

tunar

(informal: act of tuning)

afinar

(to adjust a musical instrument)

afinar

(to make more precise, intense, or effective)

ajustar

(to adjust (e.g. a mechanical or electrical device) so that it functions optimally)

ajustar

(to make more precise, intense, or effective)

sintonizar

(to adjust the frequency on a radio or TV set, so as to receive the desired channel)