New York-based violist, composer and improviser Jessica Pavone has made a speciality of writing for string quartet, though Pavone string quartets usually aim to reconfigure the conventional two violin/viola/cello instrumentation. Her 2009 album Songs of Synastry and Solitude took away one violin and added a double-bass, while this latest project looks the other way by scoring for two violins and two violas, which strips out the lower octaves. From the duo she shares with guitarist Mary Halvorson to her other composition projects, Pavone has long been fascinated by the tension caused by riding disarmingly direct melodic lines over structural obstacle courses. The five pieces of Brick and Mortar run to little over 30 minutes, and not a note is wasted. Her opening piece, ‘Hurtle and Hurdle’, establishes a chain of simple triadic patterns that gradually fall out of synch – then get reworked into an ornate overlay of lines and curves. Although all these compositions are fully realised on manuscript paper, with occasional leeway given for her musicians to move through modules at their own pace, or chose pitches from a pre-selected pool, this is obviously the work of someone immersed in improvisation. The rarefied harmonic overtones of her title-track and the trippy, irregular loops of ‘Sooner or Later’ inspire deep listening – and, once it's over, you miss it like crazy.