By 1983, the founder of the 4AD label had carved a reputation for releasing darkly gripping post-punk by the likes of Bauhaus, the Birthday Party, Modern English and Cocteau Twins. Feeling creative himself, Watts-Russell decided to cherrypick various 4AD band members to record a one-off single, Sixteen Days/Gathering Dust, written by Modern English, sung by the Cocteaus' Elizabeth Fraser and released under the name This Mortal Coil. But Watts-Russell needed a B-side and so he asked Fraser to cover his ultimate desert-island disc, Tim Buckley's Song to the Siren.
It was a lethal combination. The song is an uncannily haunting ballad, its images of the sea, doomed romance and drowning alluding to what Watts-Russell calls "the inevitable damage that love causes". Buckley's eerie original is backed by stark waves of guitar and occasional high-pitched "siren" wails (is it his voice? An extremely flanged guitar?), and his five-octave-spanning tenor – "the closest thing to flying without taking acid or getting on a plane," Watts-Russell reckons. But Fraser's version suggested she was the siren of Homer's Odyssey personified, luring lovers to a premature grave.
Well, someone was lured in, because Song to the Siren became an A-side in its own right and spent two years on the independent charts, selling half a million copies. This Mortal Coil – spearheaded by Watts-Russell with assorted personnel – subsequently released three albums of similarly intense covers and originals, but as a new boxset of their complete recordings shows, nothing ever matched Song to the Siren's knee-buckling beauty.