I studied harmony extensively in the mid to late 70's. I quit playing for a few years. I got back into it, reviewed my old lessons and bought some books on soloing. I was in Germany and needed an English speaking teacher, with a lot of flexibility since I was in the Army. In the mean time I worked out what modes to play over what chords. I just found those charts, complicated chord sheets with even more convoluted modes written in. It is no wonder I didn't get anywhere. I was doing better soloing when I only knew chords. When I found a teacher modes were only covered for modal music. Modes are very simple really, so simple that the use of them probably requires a teacher, they are the most misunderstood basic object in music theory. These threads are always as convoluted and contain as misinformation as legal advice threads. No flame to the guys who have doled out good info.