Examples of hit song ingredient 4 Chords Only

Ordinary Day - Dolores O'Riordan
https://m.youtube.com/watch?v=2m_CSxL-9E8
The bass loops (repeats) every 4 notes.
There may also me the hit song ingredient, Varispeed, on voice. A way to do Varispeed is running the tape a bit slower. The backing track is therefore lowered say a semitone. The vocal is sung and tracked at that pitch. Then at playback the tape speed is brought back to normal. So everything is in correct pitch but the voice sounds more fresh. It can also be done on software Samplitude by changing the sampling rate at recording and then setting it back to normal at playback.


This shift in frequency domain makes the voice sound younger.


Another great example of 4 Chords Only:
The sequence in bass (as heared by one of the a capella singers is:


G flat (lasting for 4 slow beats)
E flat (lasting for 4 slow beats)
C flat    ditto
G flat


G flat
E flat
C flat
G flat


Etc


Just the Way You Are - Bruno Mars, Pitch Perfect film version
https://m.youtube.com/watch?v=MpYccBQH-Lg


Another hit song ingredient here is the very rare scale used, G flat major or F sharp major. It consists of mosty black keys on the piano.