The best analogy I have for the new style of jamming is akin to remodeling a house. The expansive days of yore Type II jam is the equivalent of bulldozing one or more walls of the house and then building an extravagant extension that eats up a lot of the parcel of land you own. The new style of renovation utilizes the existing framework of the given song (the house) but adds incredibly gorgeous musical tile inlays and splashguards, strips and polishes the old wood floors, repaints in vibrant new colors and thereby breathes new life into an old classic space. It's the same old house you've lived in for years but it is somehow new and inviting once more.