Value for which a no synth is needed, but only a scalar value that needs to be set on the target node.
Value for which a Synth is required that writes its signal to a bus,
and the bus is then somehow mapped to the target node's control.
An AuralAttribute.Target describes the mechanism by which
the attribute inputs can contribute their values.
An AuralAttribute.Target describes the mechanism by which
the attribute inputs can contribute their values. It is internally
connected to the process's node. One or multiple inputs then
supply their values by calling put and detach themselves by
calling remove. The target automatically manages summing multiple
inputs. While the Value parameter for put corresponds to
a particular attribute input, its valueOption gives the
overall signal output as sent to the node. For instance,
a stream input will have a bus to which is writes, whereas
the target itself may provide a bus from this node reads.