A deluxe sampler covering the work of nearly 40 years, John Tavener: A Portrait has much to offer, including 19 musical tracks, a 46-minute interview with the composer, and a biographical essay detailing the key events and ideas in his life and work. Of primary interest is the premiere recording of Tavener's intense "Prayer of the Heart," convincingly performed by Icelandic pop singer Björk and the Brodsky Quartet. The text of the Orthodox Christian "Jesus Prayer" -- in Greek, Church Slavonic, Coptic, and English -- is set in fairly static sequences, which gradually progress through a spiritual scheme of halting trepidation, ecstatic aspiration, and, ultimately, serene acceptance. Björk was chosen by Tavener for her unschooled and unaffected singing style, and it is clear that her emotionally exposed performance meets his expectations. While her raw and breathy delivery may not suit everyone's taste, Björk deserves credit for plumbing the work's expressive depths and bringing off a difficult, highly inflected vocal line with assurance and authenticity. Naxos, in coordination with Coro, Nimbus Records, Divine Art, NMC, and Reference Recordings, has put together a handsome package that may lead listeners to seek out the original albums from which this disc was compiled, and further explore the evolution of England's most esoteric composer.