People can tell when the music is going back down to a tonic chord because it happens every time the musicians hit a high point in the song. The piece has a fluctuating tonality.
Explanation:
You can use these 3 note voicings as chords whenever you would normally apply the A minor pentatonic scale: Am7, Cmaj7, Fmaj7, Bbmaj7, Dm7, D7sus4. ... As you may know G major contains three minor pentatonic scales: E, A and B. The Am pentatonic is not so useful since it contains the C, but both E and B will work fine.
