Watch the Jam Band online guitar lesson by TrueFire from Play Bass Guitar 3: Essential Skills
Jam Band - Groove 29 is a video guitar lesson presented by Andy Irvine and is sourced from 30 Beginner Bass Grooves You Must Know.
Jam bands really started in the 1960's, and have become a highly influential part of American music history. The genre is made up of a fusion of many styles, taking from jazz, rock, R&B primarily. There is a free approach here, and tasteful improvisation within the musical context and groove are completely appropriate.