In the press materials for Streaming, his new album with pianist Muhal Richard Abrams and saxophonist Roscoe Mitchell, trombonist and laptopper George Lewis says the music made by this leaderless trio is “open,” not “free.” The difference? In Lewis’ words, “open” improvisation is all about responding to “what’s at hand” and viewing “ideas from multiple perspectives.” Or, in layman’s terms, “open” improvisers check their egos at the door; “free” improvisers might not. Whatever the case may be, Streaming is hardly free of the usual pitfalls. This kind of music-jazz sans songwriting-works best when the players achieve what I like to call mono-sound. That is, instrumental interplay that resists easy breakdown. Streaming’s second track, “Bound,” is a good example. Instead of treating the cut as an opportunity to vie for the spotlight, the three Chicago legends make themselves more or less indistinct, as if they were all part of the same droning, crackling instrument. The same goes for the percussion-heavy “Soundhear.” But just as much of this 73-minute disc lacks any kind of cohesion. Opener “Scrape,” the most unpleasant of Streaming’s five tracks, could’ve been recorded by three guys separated in isolation booths. Which just goes to show that semantics is less important than effect. After all, who cares what you call your music if it never gets a second spin?