I remember hearing people (jazzers) talk about chord substitutions. I recall hearing about using "tritone substitutions" which I can only assume means something like playing the same type of chord (Min, Maj, Dom, etc) a tritone away from the chord you're on....so, for example, playing an F# minor where you'd normally have a C Minor. It generally sounds bad/odd to do this but I assume I'm missing something or other. Maybe they're just used as a "passing chord/tone" on the way to another chord (like on the and of four, before the change??), or, maybe there's a more accurate and better sounding way to utilize such weirdness.....anyone know anything about this idea??
if i remember correctly you pretty much got the idea. the thing is i think it only works for dominant chords. sevenths and higher ones like 9 and 13.
the reason for this is the following: any dominant chord has a "defining" tritone that gives the chord it's dissonance. the tritone is between the 3rd and 7th. (ex. G7 tritone is B to F). Notice that a tritone is the same in either directions since it is 6 of the octave's 12 half-steps. B to F is just as far as F to B.
So if you shift your domiant chord by a tritone, think G7 to C#7, it has the same defining tritone.
G7 - G B D F
C#7- C# E# G# B
(E# is equivalent to F.)
As for when/where to use tritone substitutions, you're on your own there. Tell me if you learn something good...
