" data-original-title="" title="">Roswell Rudd in his work, even while his playing lacks that man's depth of character. He's rambunctious enough on the likes of "Babel I," but considering how much competition there is in even this rarefied field of European improvising trombonists, his work lacks that indefinable and ear-catching "something."

On "Babel IV," the duo indulges in an inscrutable dance, its work combining to impart a sense of stealth as the music progresses. But the result has a perfunctory air; it might not be summed up as a couple of musicians going through the motions, but it does lack the mark of knotty engagement.

"Inextricable" offers a summary of why this music usually fails to be fully engaging. Blaser's playing is "true" in that his engagement with his instrument's mechanics extends only as far as the use of conventional technique. While there might be a school of thought which argues that there's no point in playing the trombone—or indeed any instrument—if the intention is to make it sound like something else, in the case of music this naked, extended techniques might help retain the attention. For his part, Favre is a master of rhythmic nuance, but again the level of engagement between the two musicians seems perfunctory.

The title track does, at least, imply something else, even if that is only what tantalizingly might have been. Favre extends his palette, and the line between sounds tempered and untempered is stretched to breaking point. Interestingly, the music is credited to both players, and certainly amounts to the best instance of collaboration in the whole program.