Numerology, paintings, and mysticism are all in a day's work if you happen to be a European chamber ensemble supporting a pianist and a recorder player on "Sonograms".
First, I'll just say that releasing a compilation titled Sonograms under a label called Labor can really complicate a Google search.
This contemporary classical compilation is a hands-on approach to reversing the relationship that sound has with notation. Unlike a recorded birdsong, this is music that starts with abstract notation and falls at the mercy of the performer. The list of composers include some big names like Arvo Pärt, Iannis Xenakis, and Paweł Szymański. Georgi Minchev, whose work "Sonograms" inspired the whole collection, is featured here for the first time in digital form. The stars of the entire program are German recorder player Benedikta Bonitz and Bulgarian pianist Angela Tosheva.
Sonograms is a difficult listen. Not because of the quality of the content or the performances, but because it is just so aesthetically dense -- almost impenetrable, really. It's hard to recommend it for anything beyond deep academic study or yoga class (if sequenced just so), but that's better than no recommendation at all.