REPUTEDLY one of the best choirs in the world, the Estonian Philharmonic Chamber Choir and their conductor Paul Hillier alone would be reason enough to step out on a Sunday evening. But with the acclaimed UK-based vocal ensemble the Orlando Consort also on the bill, Greyfriars Kirk was packed with choral enthusiasts. Hillier, founder of the superb Hilliard Ensemble and artistic director of the EPCC for the past six years, has brought his phenomenal experience to bear on this excellent group of singers. This was most evident in the complex and challenging Scattered Rhymes by the young British composer Tarik O’Regan. Intertwining an eclectic selection of sources – Petrarch and an anonymous 14th-century English poet for the texts and fragments of a mass by Guillaume de Machaut, the most influential composer of the Middle Ages – O’Regan wove the most magical and beguiling spell with the voices, delicately overlapping and layering the vocal lines of the consort quartet and choir, and building them up to produce the most brilliant and stunning sound: in particular the pulsing effect he created, almost like an echo in stereo and ideally suited to the Greyfriars acoustic. Gavin Bryars’s haunting Super Flumina, inspired by the legend of St Mary’s Abbey in York, sung by the Orlando Consort, also filled the space beautifully whilst Rakhmaninov’s deeply spiritual All-Night Vigil, one of the main feasts of the Orthodox Church, was perfect material for the EPCC’s rich, mellow voices.