Having worked with everyone from the storied Art Ensemble of Chicago to young Chicago artists including Makaya McCraven and Marquis Hill, bassist Junius Paul has established his fluency in a wide range of jazz settings. On his double-album debut, Ism, he brings his own musical mission into focus in a wisely curated set of encounters captured between 2016 and 2019 (Paul and McCraven share producer credit). The music is full of spontaneity and experimentation, whether it’s a short episode like “View From the Moon” or “Georgia” or an album-side-length foray as expansive as “Spocky Chainsey Has Re-Emerged” (launched into the stratosphere by the seductive Rhodes of Justin Dillard). “Paris,” another longer track, finds Paul in contemplative groove communion with McCraven and Hill, while “Fred Anderson and a Half,” named for the late Chicago tenor player and mentor to so many, brings Paul into mysterious dialogue with cellist Tomeka Reid and drummer Isaiah Spencer. For a good sample of Paul’s considerable bass chops, try the extended cadenza of “Asé.”