She admits that her voice wouldn't win any prizes in the music industry. But something about the raw cadence of the vocals as Susan Philipsz sings her lamentations of love and loss strike a deep chord with audiences.
Her unaccompanied, unadorned recordings of traditional Scottish ballads have now won her Britain's most prestigious accolade in, not the world of classical music or folk, but the visual arts.
Philipsz's "sculptures in sound" have become the first instance of a sound art exhibit winning the Tate gallery's annual Turner Prize, and are likely to reinvigorate interest in the field.
Critics commented on the spine-shuddering quality of her renditions, with several moved to tears. Many noted the fragile, vulnerable quality of her voice, and remarked on the way the physical body of the sound reverberated to fill the empty gallery space. They spoke of the unnerving effect it had on the listener, that of intruding unthinkingly on a moment of private grief or overhearing a deeply personal expression of mourning.
Philipsz herself disavows the "sound art" categorisation, seeing her work as lying firmly in the field of visual art. Indeed, she confesses to disliking her own voice, and describes her work as sound installation, with the sound working as a sculptural entity inhabiting its environment physically, as a work of conceptual art that is pure sound.
"Susan doesn't consider herself a sound artist per se, but a visual artist," says Helen Little, the curator of the Turner prize, who worked closely with Philipsz to install the work. "She trained as a sculptor, and during that period began experimenting with the sculptural possibilities of sound. That became an essential facet of her practice, so that the physical presence of her sound can be felt to occupy the exhibition space."
The piece itself, entitled Lowlands, consists of overlaid recordings of three versions of an old Celtic sailor's ballad mourning the ghost of a lover drowned at sea.
Critics have remarked on how even the flaws in her voice give it depth, endowing it with a haunting quality so that, while it may be imperfect musically, it takes on heightened meaning, occupying the awkward gap between the public and private spheres.
"She uses her own voice unaccompanied, a cappella. There's no cleaning up of the recording," says Little. "You feel it's someone singing for themselves, alone. There's a tension between the public and the private aspects, combining lyrics and vocals with very emotive effect."
The exhibit was previously shown in Glasgow, where it was installed under the arches of three bridges over the Clyde river. "In Glasgow, you encountered her voice unexpectedly," says Little.
"It's a poignant experience to hear that in the dark underbelly of the bridges, with these forlorn vocals singing of drowning, and the sound ricocheting off the built-up environment."
Lines such as"my love is drowned in the windy lowlands" gained amplified meaning in the seedy context of an urban underpass, with trains juddering overhead and the huge, murky river moving beneath.
The work garners much of its power from its interaction with the space it occupies. Its "site-specific" nature means the experience of listening - deeply subjective in any case - is changed utterly by the milieu in which it is experienced.
Philipsz's sound installations have been shown at the Guggenheim in New York, the São Paulo Bienniale, and the Gulbenkian Foundation in Lisbon. Her latest project, Surround Me, sets her Elizabethan madrigals ringing out in the yards and alleys of London's old financial district.
The Turner prize show at the Tate Britain brings the work indoors, transposing the piece to the blank, box-like void of a gallery space. It offers nothing to look at. A bench and three speakers are the only objects in an otherwise empty gallery.
"Situating the sound in a starkly vacant gallery adds to the atmospherics," says Little. "The space is devoid of the visual stimuli you got in Glasgow, and that intensifies the physical encounter.
"She invites you to consider the way the sound behaves, the way it disseminates and permeates the space and gets grounded in the present reality. It isn't at all transcendental. She gets you to see things based on what you hear."
Although it may be obscure, Philipsz's art draws on a long tradition in the experimental avant-garde, originating in the surrealist movements of 1920s Paris, in the iconoclastic recordings of the Situationist International, and in Fluxus happenings.
Sound art has taken diverse, hybrid forms, drawing on conceptual art and minimalism, performance art, poetry and experimental theatre. It has involved acoustics, electronics and environmental sound, and engages with other media such as sculpture, film or video.
The medium dates back to Luigi Russolo's Intonarumori,or noise intoners, and his 1913 Fluxus manifesto The Art of Noises. "Early 20th-century movements such as the Dadaists experimented considerably in the field," says Little. "Marcel Duchamp's recordings of sounds of the city in Paris are a notable example, and the Futurist movement used it a lot."
Andy Warhol's Factory achieved a certain faddish notoriety for its attempts at sound experimentation. Most momentously, John Cage's avant garde compositions would have an enormous impact on conceptual art of the 1960s, for instance in his controversial 1952 composition 4'33", in which three movements were performed without a single note being played, with the silences intended to be perceived as the sound of the environment.
These works gain much of their effect from the way sound evokes associations in memory, as well as in the acoustic possibilities afforded by the location, and in the qualities of that environment, whether indoor or outdoor, urban or rural, built up or remote.
Bruce Nauman's 2005 sound installation Raw Materials brought the form to the Tate Modern's monumental Turbine Hall, so that the huge empty space was set resounding with spoken texts, audio tracks, and endlessly repeated words. "The readings were recorded with a kind of multichannel overlap, so that as you entered, you were completely surrounded by fractured voices," says Little.
Until then, Nauman was best known for his works in photography, performance and installation. "He no more considered his invisible sculptures 'sound art' than Philipsz," says Little.
Last month's Abu Dhabi Art Fair featured a sound installation by the New York-based collective Soundwalk, entitled Eternal Hell, which comprised recordings of ambient sound from the Rub al Khali, or Empty Quarter, the desert acoustics recreating the experiences of the English explorer Wilfred Thesiger.
Philipsz's award is likely to give new impetus to these movements. "Even though it's not a trajectory Susan identifies with, the award has elicited renewed interest and curiosity in sound art," says Little. "It's very fluid, and it's notable for the fertile cross-pollination that goes on. To some extent, the Turner prize can be seen as a recognition of the contemporary work that's being done in this field."