14.9Compare natural 11 versus ♯11

Natural 11 over G7 is:

C.

But:

B and C

sit a semitone apart.

That can work as suspension:

C → B.

But if you want a stable color rather than a suspension:

C♯ gives the bright ♯11 sound.

So:

C = sus/11 tension

C♯ = ♯11 color

Hear them separately.