The Chicago Underground collective has been a fairly long-standing out-jazz combo from the Windy City. Since the late '90s, its revolving door lineup has produced releases by the CU Orchestra, Quartet and Trio, but it's the Duo lineup—made up of the only constants, cornet player Rob Mazurek and drummer Chad Taylor—that has made the most albums. This ever-expanding and contracting format has created some fascinatingly divergent records, but throughout it all, Mazurek and Taylor have retained instantly recognizable traits and always kept the quality level high. However, when Mazurek moved to Brazil shortly after 2006's In Praise Of Shadows, one wondered if this excellent pair was calling it quits. Taylor relocated to New York, playing with, among others, Marc Ribot and ex-Ayler bassist Henry Grimes in Spiritual Unity, as well as Iron And Wine's touring band. But the CU albums are a special part of what makes Taylor such an engaging percussionist, so it is with excitedly open arms that we welcome Boca Negra.

Since their second duo record Synesthesia in 2000, the group has utilized more and more electronics, in the form of science-fair synth washes, pitch-shifting effects on Mazurek's Don Cherry-inspired cornet trills and spy-movie chase-scene bass loops. Boca Negra has plenty of these touches, but as always they augment and adjust rather than dominate the band's voice. The real show is this pair's chemistry, and it is a beautiful one to behold. Whether cagily delivering oblique jabs of random sound at each other; riding a tight, specific groove with deft touch; floating in a sea of Doctor Who-era ambience; or blaring with full audio force, the Duo are relaxed, in touch, and broad and beautiful in their range. The "Chicago" in their name may now be more decorative than descriptive, but it's clear from Boca Negra that no amount of physical distance could drive a wedge between the cerebral connection these two share.