scale degree
the position of a particular musical note on a scale relative to the tonic
subdominant
fourth tonal degree of the diatonic scale, between the mediant and the dominant
submediant
the sixth degree of the diatonic scale, between the dominant and the leading tones
dominant
fifth scale degree of the diatonic scale, between the subdominant and the submediant
tonic
tonal center of a diatonic scale
secondary dominant
harmonic device in Western music
supertonic
second degree or note of a diatonic scale
mediant
third scale degree of a diatonic scale, between the supertonic and the subdominant