Fans know that it isn’t the shape or length of the jam so much as the freedom and possibility jamming represents. The tracks here aren’t about technical mastery so much as they are about the ability of a band to spontaneously conjure a space in which they become one—no simple trick, when you think about it. Add to it a sense of groove and ease that has guided jam bands since before they had a name and you end up with a sound as comforting as it is exploratory, as down-home as it is far out. Follow it. We update picks regularly, so if you hear something you like, add it to your library.