The tonic, also known as the tonal centre, is that particular note (and the chord built on it) on which the music is stable and at rest – it feels like home. Melodies and chord progressions are pulled towards it so no matter what happens throughout a piece or a song, the music tends to come back to it.
What are tone centers?
A tonal center is the note your harmony and melody will sound at home at; while guide tones are the notes that not only greatly define the harmony at that point, but also typically help lead from the current chord to the following chord.
What is a key center in music?
Key Centers are the group of chords that make up a given Key. They can be expressed in Major or Minor forms, as well as Modes (more on this later), and they are the absolute key to understanding improvisation.
Is the tonal center the key?
The notes that a major key uses tend to build “bright”-sounding major chords. They also give a strong feeling of having a tonal center, a note or chord that feels like “home” in that key. The “bright”-sounding major chords and the strong feeling of tonality are what give major keys their pleasant moods.