Step-wise walking bass for tritone substitution

1. How do you calculate tritone substitution?

How do you calculate tritone substitution?

The tritone substitution can be performed by exchanging a dominant seventh chord for another dominant seven chord which is a tritone away from it. For example, in the key of C major one can use D♭⁷ instead of G⁷. (D♭ is a tritone away from G).