Watch the Sub or Lead with a Tritone online guitar lesson by Fareed Haque from Solo Guitar Handbook
Principle #5: Sub or Lead with a Tritone
In this section we're going to talk about the much misunderstood, overly complicated, and crazy sounds of the tritone substitution. You can find all sorts of theoretical explanations of this in theory books, but really this evolved organically through the traditions of jazz.
Back in the early days of jazz, the tuba was playing the bass, and the tuba player would just sit on the bass note. They'd often times get bored, and eventually might succumb to the temptation to play a little chromatic run to the next, using a leading note into the next chord. In doing this, he accidentally created a new sound that is now a cornerstone of jazz.
Now, we'll take our progression from Amazing Grace and add in some tritone subs. Don't be scared! See chart.