Hunched over and almost invisible, a man coaxes unearthly wails from a saw. At least, it is presumably a saw; it could be a voluble species of owl with some sort of pedal attached, for all anyone can see. The man is Paulo Zappoli, or he may be. He is certainly also Pall A Jenkins, and he and his band have begun to reinvent both themselves and their sound on their fourth album, Amore del Tropico.

Trekking south from their origins in funereal San Diego swamp country, they find themselves, it seems, in Brazil, casting the bitter fallout of a failed relationship as a murder mystery most noir. It is territory poised so exquisitely between pastiche and evisceration that the most obvious adjective for it is Lynchian. Tropics of Love is a demented, malarial bossa nova, disorienting and heady as the affair it describes. A Cry for Love, like a blasted version of an old Dan Penn/ Spooner Oldham soul song, swoons heavily, while a fretful violin blows in as if from an Appalachian murder ballad, and Zapppoli gives up a piercing wail over the final Vegas flourish.

The songs of Black Heart Procession - as their name implies - tend to proceed at a magnificently stately pace, like regal thunder. There is a bleak rapture to be had as the violin negotiates brilliantly discomfiting glissandos in Waterfront (The Sinking Road) and Zappoli cries "You came/ You failed/ And it means nothing," perhaps the archetypal Black Heart Procession lyric, during Sympathy Crime. There is subtlety in the assault, though. Old Kinda Summer is a delicate waltz: remorseful piano and violin conjuring rain-splashed sidewalks, garish neon and the wandering gait of a heartbroken gumshoe consumed by his own inadequacy.

Like Delgados, one of the few other bands to make use of waltz-time, Black Heart Procession know that to stray from rock's tyrannical 4/4 slog conveys a seductive otherness. Love's a filthy business, they are saying, but there are comforts to be found in sadness.