The sinuous sound of Adam Walker’s flute wove its way across the audience from above and to the left of the organ in the Sydney Conservatorium of Music’s Verbrugghen Hall, opening the final concert of the 2019 Musica Viva Festival with a sense of ritual and mystery. Debussy wrote his solo Syrinx for flautist Louis Fleury, as incidental music for Gabriel Mourey’s play Psyché, inspired by Greek mythology, and while it may first have been played offstage, it has become a centrepiece of the flute repertoire, Walker’s high perch paying tribute to its theatrical origins. With sweet tone and velvet low register, the British flautist captured the stillness and magic of the work, which in this concert became a companion piece to Edgard Varèse’s Density 21.5 – an equally important milestone in solo flute repertoire, written in 1936 (and revised in 1946), and named for the density of platinum – which Walker dispatched with a darker sound, more urgent intensity, ringing fortes and resonant key slaps from the other organ’s other side.

The atmospheric first half of the concert saw Walker’s performances bookend a bracket by Andrew Tyson, who drew splashes of refracting colour from the piano in Messiaen’s Première communion...