I have been reading a good bit about blues music (my personal favorite) and blues playing and notice that they mention 'a triplet feel' a lot. They also talk about 'shuffles' and, of course, twelve bar blues. I think I understand twelve bar blues but I am lost on triplets and shuffle. Can someone explain what those terms really mean?

Also, I know that solos are based on pentatonic scales, right? Yet when you listen to solos, they seem to jump all over the place - from one scale to another and then to another and back again. Is that what I am hearing or is it my imagination?

Thanks.