But that technicality aside, this live First Symphony recorded at the 2012 Lucerne Festival is a mandatory listen for any self-respecting Brucknerhead. Abbado arrives at the rare ‘Vienna version, 1891’ after recording Bruckner’s original 1866 ‘Linz’ version three times, twice with the Vienna Philharmonic. Wand, Chailly and Rozhdestvensky also opted for Vienna; everybody else, from Karajan and Jochum to Mario Venzago and Simone Young, prefers Linz. And at a time of life when most conductors would be happy to present their settled view, why Abbado’s latter-day conversion?

He is, you feel, utterly beguiled by the beautiful mysteries of this symphony’s split-infinitive harmonies and carnival-mirror gestures. Far from taking a settled view or even considering such a luxury desirable, the symphony has clearly been resonating through Abbado’s imagination for decades (his first recording dates back to 1972) and here he dives ever deeper into the eddy, grappling with an idea of what Bruckner’s First symbolises both on its own terms and as a pointer towards the composer’s future.

Abbado needs you to understand the extreme degree to which Bruckner’s Scherzo is wrong-footing and rum. His bright tempo rocks: those bars where the dynamic levels drop and gap-toothed holes appear in the ‘3’ feel like orchestral hiccups, like oddball in-time syncopation; the usual narrative of call-and-response is all downside up. His Adagio obsesses over Bruckner’s arch, scrupulous detail shading in the long haul. An example: in bar 7 of the score, 0'39" on the CD, listen to how Abbado deals with Bruckner’s accented p moving to an accented pp as the melodic line abruptly opens up from minor seconds to land on a beaming major third. Each note is massaged with an essential new fragrance. Every harmonic chess move counts.

Bruckner’s First begins not with its head in the tremolo string clouds but with stampeding strings that sprint towards an almost immediate point of climax, and Abbado does nothing to rein in this music’s red-blooded walk on the wild side. Typically, in the finale, small details – the differential between ff and fff for example acutely observed – bump into grandstanding set pieces. Approaching the final pages, check out the Mexican wave of flute overtones that corkscrew above the orchestra (14'10" onwards). Listening and marvelling is really the only option.