the last point is true. but that's not how i think of busses, or have ever thought of them. its thinking of them in the way you describe that has led them to end up being such 2nd class citizens in the hardware mixing world. it still shares with a strip the notion of some kind of "flow" - data arriving from somewhere and then being delivered to somewhere else. the "unity gain summing node" describes, in software terms, a memory buffer and a method of storing data there. that by itself doesn't seem worthy of being called a "bus" to me, and indeed, its not really all that the terms means in the analog world, where busses are routinely used to get data from one place to another. you send a signal to a bus (typically by pressing a button), and then collect it from the bus (typically by plugging a cable into the output connector for the bus). thats not really very different from the way you send a signal to a strip (physically, you plug a cable into the input connector for the strip) and then direct the signal to one or more outputs (typically by pressing a button). the strip is normally allowed to include some signal processing, and the bus conventionally does not. other than that, they look like pretty much the same idea to me. its a little different in the analog world, where you have to work to get multiple "store" operations to be anything except unity-gain summing, and where providing multiple pathways for data to flow down has real electrical implications. --p