Here we were, bags packed, maps crumpled, waiting for another journey to an unknown destination. The Kronos Quartet has always displayed an appetite for the unorthodox, so it made perfect sense to mount the collaboration with Azerbaijan's master singer, Alim Qasimov, during the Ramadan Nights season.

In the end the encounter, funded by the Aga Khan Music Initiative, never quite shook off the ambience of a work-in-progress. As in the meeting with Asha Bhosle, the Indian playback singer, David Harrington and his colleagues are groping towards a new vocabulary, attempting to fuse what Bobby McFerrin has called “paper music” with the free-flowing forms of non-Western traditions.

If the Bhosle project could draw on the assumption that the audience was acquainted with Bollywood, Qasimov's austere modal invocations represented a much broader cultural leap. Replete with images of suffering and devotion, his classical mugham repertoire offers fewer footholds for outsiders. Even with surtitles, this was no evening for fainthearts.

If the Kronos arrangements - the work of the New York-based composer Jacob Garchik - seldom rose above the level of embellish- ment, there was no mistaking the passion of the ensemble's playing. In My Spirited Horse Harrington's violin whinnied and raged like some impatient stallion. Behind him, seated cross-legged on a platform draped in exotic shades, Qasimov and his daughter Fargana maintained an ecstatic flow of laments and exclamations while their compact group of musicians added restrained punctuation.

The Kronos's most potent sorties came in a series of densely atmospheric pieces, including Aleksandra Vrebalov's Sketches From a Balkan Notebook and the haunting Flugufrelsarinn by the Icelandic group Sigur Rós. Fragments of electronica were smuggled into the mix and Jeffrey Zeigler's cello sometimes took on the vigour of a jazz double-bass. On the extract from Ram Narayan's Raga Mishra Bhairavi, Hank Dutt's serene improvisation shepherded us into the transcendental mists.

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