David Rothenberg, familiar to ECM listeners through his fascinating duo album with Marilyn Crispell, has constructed one of the most idiosyncratic vessels in which to sail the waters of improvised music. He excels at expanding his own terms to suit an ever-changing roster of natural musicians. The German field recording label Gruenrekorder is the host for this rather different collaboration, which combines Rothenberg’s clarinets with Turkish sound artist Korhan Erel on computer and iPad, along with nightingales fed live from the parks of Berlin. Anyone who has followed Rothenberg’s career will know of his mythical explorations of bird song in the book Why Birds Sing and its accompanying CD. More recently he has done the same with whales and insects, but the birds have been a regular point of return.

The liner notes of Berlin Bülbül (the second word being Turkish for “nightingale”) riff off these birds’ distinct ways of…