This ECM disc features two works by Russian composer Alexander Knaifel, who like his former Soviet compatriots Gubaidulina and Part has set off on an overtly Orthodox path in his mature career. Knaifel"s music is purely in the avant-garde tradition with its innovations of form and conception of silence as an functional part of a piece, but his music features a strong basis on triadic harmony and cathedral-like atmospherics that make the music here accessible for all. The Keller Quartet and pianist Oleg Malov perform on the first piece, while the second features soprano Tatiana Melentieva and technician Andrei Siegle."In Air Clean and Unseen" for piano and string quartet (1994) is divided into three movements. The first consists of sparse, pointillistic piano with the tiniest touch of strings, and the second features only strings. One would expect the two to finally meet in some bold way in the last, but no such thing occurs. Instead, the piano again takes the dominant role, and the strings again hide in the background. Knaifel"s interest here seems to be pure sound instead of the clever interaction of parts.