Harmonic alterations

Music often undergoes harmonic changes towards the end and thereby creating a greater intensity, attention, and climax. In a rock/pop contexts, for example it is common practice to transpose the song, or maybe only the chorus a semitone or a whole tone upwards. In "We Shall Overcome 'there is included two special conclusions (Am instead of C and later on Ab instead of C). In Chords On Piano 1 page 64-65 there are other examples of harmonic changes in the conclusions. Besides this harmonic change in the end there is also ritardando..

We Shall Overcome (conclusion)