Some artists are fathomable – their aesthetic fixed in time, their contribution easily parsed, the work highlights easily identifiable, listable, digestable.

That is not Paul Bley. The Montreal-born pianist, who died Sunday January 3 at the age of 83, carved one of the most unusual paths through jazz and improvised music. He was likely the last musician alive who could claim having performed and recorded with bebop trailblazer Charlie Parker, pre-bop legends Ben Webster and Lester Young and such post-bop luminaries as Sonny Rollins, Charles Mingus, Ornette Coleman, Jimmy Guiffre and others.

Bley evolved constantly over the course of seven strikingly productive decades, and his evolution took him into strikingly different musical realms. He made definitive recordings in many realms but is not rooted in any one place, not part of a single “school.” His hallmark is more an attitude, a broad approach to music that’s applicable to every improvisational endeavor: He brought what the music needed at each moment.

He had all the language of jazz in his backpocket, but did not use it indiscriminately – in a solo setting like this 1988 recording for Steeplechase, he would inject the faintest hints of blue into music that was otherwise beautifully reflective, almost overwhelmingly placid, and the reference would enhance the desired mood.

So….he could clearly play in the key of sweet.

And he could swing fiercely, stitching together lines that felt garrulous and expansive but were also needlepoint precise.

In his freer solo playing, he cultivated a zone of contemplation that was profoundly lyrical, with long arching melodies, and then would happily veer into technical inventions that seemed almost unhinged, yet governed by an intense logic. Follow a Bley solo closely, and you hear the main thought mulled and eventually exhausted with a kind of woodworker’s patience. Running alongside that, often threatening to overshadow the big idea, are irreverent glances backward at jazz history, knots of harmony that suggest music’s future, and moments of effusive fury so dense they defy transcription.

What’s most inspiring about Bley is the way he kept going. He chased music of many forms and most of the time outran it, mastered it, refracted it through his lens until it could belong to nobody else. He made beautiful sounds that seem fully written out, through composed, but were birthed spontaneously, in the moment, with a recording device running. To illustrate this I looked for something from his 1986 recording Fragments (ECM), but didn’t find. That’s a shame, because it’s one of those deep records that sounds like nothing else. Here’s another….

Each of his recordings shows a different aspect of Bley’s intellect, a different curiosity. If they’re united, it’s not by style or genre or personnel. It’s by philosophy.