Hi Tomo,
At 17:57 while B-7 is "playing," are you doing the "b9 trick" (i.e., D# (M3), F# (5), A (b7), C (b9)) as if the chord were B7? That's the only way I can conceptualize what you are doing because it seems to sound good to sometimes solo over that vi minor chord as if it were the V7 of ii.
thanks
Here is Tomo's comment:
"Thanks for your post. Think about B minor blues. (Watch the 'Take Heart' videos for demos of B- blues rhythm guitar and soloing.) I play B-7 to B7 in the fourth measure. This B7 resolves to E-7. You can play M3 5 b7 b9 over B7."