Watch the Ridin' That Train online guitar lesson by TrueFire from Play Rock Guitar 4: Rhythm Approaches
Ridin' That Train - Overview is a video guitar lesson presented by Andy Aledort and is sourced from Jam Night Vol. 3.
Another essential band who's music is essential to just about every jam night is the Grateful Dead. And since they are the virtual kings of the "jam" world, it goes without saying that their music is perfect for extended improvisational exploration. The Dead often build song structures and chord progressions from very simple forms, sometimes twists on the blues or standard folk-type progressions. A good example is the song, "Casey Jones," and this jam track is played in that style.