Watch the Symmetrical Diminished online guitar lesson by Chris Buono from Modes That Matter
When it comes to V7 chord applications these last two scales are closely related to other heptatonic modes that matter. Taking a look at the symmetrical diminished formula against the altered scale you’ll see the only difference is where sym. dim. has a 5th and 6th degree and the altered scale only has a #5/b13 degree. Otherwise they're the same notes. Coming from the same point of view the only difference between the whole tone scale and the Lydian b7 scale is in oddly coincidental converse. Looking at both formulae side-by-side you’ll notice where whole tone has a #5, Lydian b7 has a natural 5th and 6th degree. Weird, right?
A great way to take advantage of this trivia is to shed playing each related pair side by side. Try exploiting these anomalies by using them as the junctures where you make the shift from one scale to other. When playing in a cadence situation such as this one just don’t get lost and forget to resolve!