Lee Konitz, whose career dates back to the '40s, is strongly associated with cool jazz, but he’s also played in free settings. Konitz has recorded duets with a number of artists, and the 2011 release Insights includes six duets with German pianist Frank Wunsch, as well as three unaccompanied tracks. These recordings are from the late '80s and early '90s, showing Konitz in fine form. “Thingin’” is based on the chord pattern of Jerome Kern’s “All the Things You Are.” Konitz has recorded many versions of this piece, and it’s a delight to hear him improvise with no accompaniment—the better to savor every nuance of his exploration. (He’s also compelling on the other two solo outings: “Three of Four” and the title track.) “Frank-lee Speaking” has an edgy, searching quality; the back-and-forth between the two musicians is quietly riveting. A version of Cole Porter’s “I Love You (Mexican Hayride)” has old-school feeling that's far from rote. One standout, Wunsch’s “Echoes d’Eric Satie,” is a nice slice of chamber jazz.