Free jazz is often seen as an old man’s music; even players considered part of the new generation seem to be going gray. Pianist Matthew Shipp, for example, will turn 60 in December, and drummer Hamid Drake recently celebrated his 65th birthday. But there are some young musicians taking up the mantle of the music and carrying it forward. One of them is Polish multi-instrumentalist (he plays alto sax, flute, and various clarinets) Mat Walerian, currently living in Brooklyn. He’s connected with Shipp, Drake, and William Parker, and made four albums since 2012 for the ESP-Disk’ label (and appeared on one of the pianist’s releases, Sonic Fiction).