The use of major 9ths, major 7ths in Bach's music

Mass is B Minor - Bach
https://m.youtube.com/watch?v=7F7TVM8m95Y#fauxfullscreen


So much time can be given studying the full score or piano arrangement score.


It's all there. Almost all chords found in modern pop music.


For example G major 3rd major 7th, ie G B D F# at the first few bars of intro.
For example at 0:32.


Then for example 9ths like:
E bass F sharp high and the third ie G added
For example at 0:19


Or


F sharp bass, with F sharp, A, C sharp and prepared G sharp


See also how choir groups repeat the same melody with time delay starting from a different note for example a perfect 5th above.