Unfortunately, often nervous and nölig, rarely relaxed

That it to this "Impulse! 2-on-1" disc of the two albums "Mysteries" and "Shades" of "American Quartet" came from Keith Jarrett, is almost logical. The two recorded in December 1975. Both plates are stored in itself quite short and also very similar musically and stylistically. In addition, both times playing the same line-up: The quartet is completed by the Brazilian percussionist Guilherme Franco. In "Mysteries" (in the play "Flame") plays Jarrett also flute - as so often when he changes his tribe instrument piano, not necessarily with very convincing results.
In general, the jazz of "American Quartet" is rather used to. Avantgarde, fusion, bebop, free jazz ... all that goes into each other, something lighter, often a bit more strenuous to listen. The problem that I have with this kind of jazz music is that the instruments are played, although all virtuosic, but somehow in my ears usually wants to hire no harmony or at least a recognizable musical line. On the "Mysteries" half of the disc, this most likely succeed in convincing even less the play "Everything That Lives Laments", while the long title track, as well as "Rotation" and "Flame". Very nervous and frantic, the Sax in "Shades Of Jazz", the longest track of the second CD-half. But the other pieces, "Southern Smiles", "Rose Petals" and "Diatribe" (a terrible song!) Are traversed by the sometimes very nöligen saxophone Redman. However, when the saxophone silent and Jarrett's piano holding the melody, on the other hand develop quite relaxed sounds like the middle part of "Rose Petals".
Who provide a brief insight into the work of the "American Quartet" is enough to be "The Impulse Story" recommended. In it, there are probably best pieces from the eight on the "Impulse" - Label published plates of "American Quartet" together.
Updated in April 2013: I was probably a bit too strict. As before, I especially liked the "Shades" pieces of CD little and Redman saxophone is often really "tough", but at least I now find a little more access to this kind of jazz. And "Everything That Lives Laments" is really a great number. An addendum star!