Basic, and I think the solid bedrock to understand all the more complicated progressions. As in the movie "Laura" the detective takes Laura in for questioning at the police station and afterwords says, "I just needed official surroundings." Well I need expert official knowledge and experience to truly confirm what needs to be played. Let me make the I chord A, the IV chord D and the V chord E. The I chord is easy in pop, rockabilly and blues using a A major, pentatonic or blues scale but then the IV chord arrives and uhh..., does one play a corresponding D major, pentatonic or blues scale in any of the five positions and also do the same with the V position E? Sorry it seems such a dumb question but I do think the answer will help a lot of just starting out players. Thanks.