The first disk, recorded in Berlin, features the largest group of improvisers, including the voices of Lembe Lokk and Cymin Samawatie , Korhan Erel on iPad electronics and even an oud played by Wassim Mukdad. For the most part though, and exclusively on the second disk recorded in Helsinki, it's the clarinet and electronic manipulations of Rothenberg himself, alongside the beautifully recorded calls of the nightingale. Recording with a wild animal makes the notion of rehearsal somewhat redundant, and so what we have here are two collections culled from multiple improvisation sessions, and as you might expect this produces a mixed set of results. Indeed the players seem to be finding their feet on some of the early tracks starting with The Boori Sound and Dreaming Slow where Lokk interjects with the Nightingale in a call and response fashion.

Undoubtedly, the sound initially strikes the ear as odd; sparse, with the bird calls allowed centre stage and the other instrumentalists joining and leaving as they see fit. Things begin to come together on the longer pieces that make up the middle of disk 1. O Bulbul, Your Love and The Nightingales are Drunk both feature more varied and active interventions from the ensemble; in particular Korhan Erel's iPad electronics which scatter distant percussive trills and fragments of pre-recorded acoustic instrumentation across the mix, lending these piece an extra depth that has you forgetting they are being recorded outdoors. The latter composition is subtly layered with recycled phrases from the clarinet and Lokk's voice. Though the nightingale sounds sober, there's a blurred, pleasantly inebriated drift to the ensemble's playing that's almost dream like; with Rothenberg's clarinet oozing out several memorable melodic phrases. The album title track is another highlight with Cymin Samawatie on voice, her serpentine Persian lyrics dovetailing (pardon the pun) superbly with Erel's electronics, which at times are redolent of Akira Rabelais' classic Spellewauerynsherde. The disk closes with an amusing incident when the Berlin police show up, no doubt to find out who these odd people are recording with the birds at 1am!

The second disk, recorded in Helsinki, features Rothenberg almost entirely solo with a variety of instruments and noise makers including reed warblers and an ancient Norwegian flute called a seljefløyte. Rothenberg muses in the sleeve notes: "Does the bird get this?". Certainly they should be able to comprehend if they're able to make something of the composer firing their own calls back to them in reverse or at slow speeds, as he does with the aid of the iPad on Elektro Repeet. All the tracks on the second disk bar the last one were recorded during a single trip to Helsinki in 2016 and thus benefit from a greater degree of consistency in approach compared to the first disk which features recordings made over several years. Rothenberg shifts for each track from one set of instruments to another. From his clarinet to the seljefløyte and from there onto a furulya (a type of recorder), bass clarinet, electronics and the warblers. It's tempting to hear more synergy between the human and animal parts of this project than are perhaps actually present. Then again jazz and contemporary composition are full of dissonant recordings where one wonders if the players were in the same time-zone, let alone the same room when they recorded it.

There's a surreal, almost whimsical side to this project which has a grown man going outside to play along with the birds. But as you listen to these pieces and the bird calls begin to slide in an out with the players it begin to click and you can imagine that impromptu ensembles of blackbirds, nightingales and humans are indeed striking up a most occult kind of jazz music. Ballad with Nightingale and Mosquitoes adds violin to Rothenberg's clarinet; the strings intervening as short bursts darting around the calls of nightingale, which actually seems to lead the other two players with constant shifting between tonal and textural sounds. If you focus your attention on the birds you can see why someone might want to attempt a recording of this type. The range and clarity of their calls is extraordinary, going from repetitive chirps to melodic riffs, percussive trills and many sounds difficult to describe. The last track on the album is a departure from what went before. It's a studio composition using bass guitar to accompany Rothenberg's computer manipulated recordings of the nightingales. Consequently it lacks all the beautifully naturalistic quality of the previous tracks. It's a fun listen with the bird calls warped into loops or animated into more easily controlled samples.

At nearly two and a half hours of music Nightingale Cities is a sprawling culmination of a project that's clearly very close to Rothenberg's heart. There is material, particularly on the first disk, that manages to raise itself above the slightly whimsical premise of the project. However, many of the recordings here fail to hold the attention for those not versed in the complexities of ornithological vocalisation, and with the variety of material, it perhaps could have done with being distilled a bit more into a single disk. As it stands, Nightingale Cities is a record to get lost in, slightly baffled and occasionally come across a real gem of interspecies synergy.