People often talk about particular jazz labels having an aesthetic, a through-line that encompasses most if not all of their releases. Very few labels have been as convincingly tagged this way, in the public mind, as ECM. For five decades, they have been seen as the home for a particular sort of stately, reserved, starkly beautiful jazz that politely requests your focused attention — their CDs begin with five seconds of silence, a sort of cooling-off moment between whatever you were listening to before and whatever’s about to come — and rewards it.