As a little girl, Kaija Saariaho often heard music as she was falling asleep — so she asked her mother if she could have a quieter pillow. The sounds, of course, were in her imagination, and in the intervening decades the Finnish composer went on to write music that seems to drift in gently from the unconscious, with the strange and otherworldly beauty of a dream. But it’s not just atmospherics; Saariaho herself was at the Phillips Collection on Thursday night for a performance of her music by members of the Canadian Opera Company Ensemble Studio, and it was clear by the end that there are few living composers with such subtle insight into the human psyche.

The evening turned out to be largely about love. In “Lonh,” a work for soprano and electronics from 1996, Saariaho combined a medieval love poem (beautifully sung by Jacqueline Woodley in the ancient Occitan language) with an electronic score that manipulated bells and bird song to evoke a distant and almost luminous landscape. “Quatre Instants” for soprano and piano was more urgent and compelling — an “emotional journey,” as the composer put it, through the bliss and terrors of love, from the poignant “Longing” to the anguished cri de coeur of “Torment.”

The pianist Emanuel Ax commissioned Saariaho in 2005 to write a piece for him that would have, as she put it, “not a tune, exactly, but a strong sense of melody.” The result is the engaging “Ballade,” a sort of hyper-sophisticated Nordic blues full of sweeping gestures and moody near-melodies, which received a rich, flavorful reading from pianist Elizabeth Upchurch. But the most gripping music of the evening may have been the duet from “Grammaire des Reves” — based on texts by Sylvia Plath — that explored the sometimes-warring, sometimes-integrated sides of the unconscious. Soprano Mireille Asselin and the mezzo-soprano Rihab Chaieb turned in a spectacular performance as two halves of the same whole, balancing tension and synergy as they clutched at each other and drifted apart throughout the work.

Brookes is a freelance writer.

Finnish composer Kaija Saariaho. (Maarit Kytoharju)