Hi all,

I'm not sure if these terms are identical, or change depending on context, but is there a difference between:

1.) the "Tonal Center" and the "Tonic" - are they one and the same
2.) the "Tonal Center" vs. the underlying Scale or Mode a song is based on ?

And when is writing a 'song' or piece in C major, then changes to C minor, is this a modulation, or a change in tonality, or a change in key, or a change in tonal center ? How is this type of change described accurately among trained musicians ?

Thanks in advance,
Joe V.