Guitar duos rarely have the edgy excitement that this one promises. Chicago legend George Freeman, a sui generis stylist if ever there was one on the instrument, is prized by young listeners who have had their heads spun by his soul-jazz experiments from the ’70s, and fans who have never heard guitar lines of such keening, bop-charged expression. (Few albums have lived up to their title more than Freeman’s 1999 effort, George Burns!) At 87, decades removed from playing in local bands behind Charlie Parker and Lester Young, the man can still cut the mustard. Mike Allemana, who was the longtime guitarist and musical director for George’s brother Von, is equally comfortable playing mainstream bop and unleashing his own meticulous harmonic inventions. One of his crowning achievements was arranging original compositions by the late and lamented “Vonski” for a 2011 memorial concert in Millennium Park. He’s currently in the PhD program for ethnomusicology at the University of Chicago, which tells you how globally far-reaching he can be.