New To Tritone Substitutions

[mark ates]

The tritone substitutions sound incredible; but I'm a bit confused. In the 3rd measure of "Misty", why does the A7 work? I had the mistaken impression that this substituion worked when going from the 2nd to the 5th (ie., since this song is in E-flat, it should work when going from F to B-flat ??). Can someone help me understand?

[dadolfin]

The tritone substitutions sound incredible; but I'm a bit confused. In the 3rd measure of "Misty", why does the A7 work? I had the mistaken impression that this substituion worked when going from the 2nd to the 5th (ie., since this song is in E-flat, it should work when going from F to B-flat ??). Can someone help me understand?

"A" would be the tritone of Eb, so the A7 chord would work going to the 5 or Bb. I think I am correct on this.