A bass line can escort many melodies

Or many melodies can escort the same bass line.


There as many examples one of them is bass going up in steps of 4th intervals, (harmonic chain).


The example used on this post is step bass. Bass going down step by step the scale.


In fact the following musical examples all use the same scale, C major. So bass goes Do, Si, La, Sol, ...


Air on G string - Bach, arrangement Lousier
https://m.youtube.com/watch?v=14AhD3xdoMk


Piano Man - Billy Joel
https://m.youtube.com/watch?v=gxEPV4kolz0#fauxfullscreen
(In both above examples a higher part E caries on creating an F major 7th chord when bass goes down to F. Fa La Do Mi. This is exactly what Bach is doing on the original Air in G string in D major. The beautiful chord created is correspondingly G major 7th, G B D F#).


Unchained Melody - North, Zaret, Righteous Brothers, producer Phil Spector
https://m.youtube.com/watch?v=qiiyq2xrSI0
(Similar effect with respect to time, the bass going down 2 steps).
Again when bass becomes F, melody sings E (my da( E )rling...) to create the fabulous F major 7th chord).


Don't Let it Show - The Alan Parsons Project
https://m.youtube.com/watch?v=gzb6bC_ZVJo


A Whiter Shade of Pale - Procol Harum
https://m.youtube.com/watch?v=Mb3iPP-tHdA


Sowing the Seeds of Love - Tears for Fears
https://m.youtube.com/watch?v=VAtGOESO7W8
(Do, Si, La, Sol, Fa bass is used in the chorus. Verse bass is going down step by step the G minor scale.)
Towards the end of the song 2 melodies are used together with the same bass line.


Listen also to Viva La Vida - Coldplay, producer Brian Eno


See also:
Bach Bass Rules, instructions of Bach to his students:
https://normanschmidt.net/scores/bachjs-general_bass_rules.pdf