Furtwängler’s father was an archaeologist who assisted Heinrich Schliemann in the uncovering (some would say imaginative reconstruction) of the temples at Olympia. During stretches of his Piano Quintet, I was cast back to a strange vision of university days, sitting in a lecture theatre while Schliemann’s unearthly form mumbled his way through a slide-show of excavation reports, shards of clay and stone. ‘Of ritual significance’ was the term often applied (and now equally derided) when historical methods fell short.

And when the ghosts of Beethoven and Brahms and Bruckner emerge from the gloaming of the Piano Quintet, what might be their significance? The finale redevelops the First ‘Razumovsky’ Quartet’s opening theme; in turn, the chromatic arch of the Adagio bears a more passing resemblance to Beethoven’s ‘thème russe’ from the same Quartet. ‘I am a tragic writer!’ responded Furtwängler to one of the Quintet’s early private listeners, and its subtext is plain. The why, the need for the work’s existence, remains elusive. After making initial sketches in 1912, he took another 23 years to complete it: the wonder is that its three sprawling movements hang together as much as they do.

First released on CD in 2004, the present recording is reissued on a Blu ray disc of three audio formats. At a friend’s house I sampled Tacet’s proprietary technology of ‘Moving Real Surround Sound’. The effect is every bit as unsettling as the eyes of Vernon Ward’s ducks, following Pete and Dud around the gallery; back at home I found that the 2.0 stereo is already distinguished by an unusual depth of field.

The performance itself is no less distinctive: at over 80 minutes, it is almost a third as long again as a rival recording from the Sine Nomine ensemble on Timpani. Enough already, you might think, when the piece is so incurably prolix. However, Furtwängler the composer is not be rushed. Furtwängler the conductor understood better than most how a slower tempo may breathe spontaneous life into the narrative complex of a Beethoven allegro; so, it appears, do the Clarens Quintet. Recommended with caution to keepers of the Furtwängler flame, and to those who are martyrs to their hi-fi.