There was so much saliva about 50 seconds in that I worried they were going to run out of it but then they dried, they hissed, Phil Minton mosquito’d, Audrey Chen made a noise like a budgerigar in a balloon, and I noticed that the rapport between the two performers was developing a history. A long improvised production like this one doesn’t have a score but it has a history, it thickens with the weight of its own past. In By the Stream it doesn’t have a climax or an obvious story, it flares and sinks, the two performers make their mouth noises, the slurp, the suck, the vocal squitter, the wet/dry contrasts, or loud/soft duets, not words, never words, though sometimes they seem close to words (“to”, from about 1:40 on) and Minton has performed words before, doing Blake and Finnegans Wake. He is a British vocalist and a jazz trumpeter. Chen is a conservatory-trained American singer and cellist. No cello here, no trumpet, no conservatory, they manage their mouths like machines, pressing the musculature around the passage of the air, shaping the album around mutual responsiveness, see, I hum, you complement me with a buzz, I build, you help. Inuit katajjaq would be an obvious stylistic model but they don’t seem to have borrowed. They have their own repertoire of habits, repeating motifs without copying themselves exactly. Put the titles of the tracks together and you produce this sentence: “It’s all starting to make sense there are other things to do as well by the stream.” Deduce that they set out to develop their duet with as few references as possible to exterior-established conventions. That idea could have trapped them inside limitations of their own, smaller than any set of rules from the outside, but their range of sounds is so large that they triumph.