“Here, the unattainable becomes real…”, words from the Chorus Mysticus that closes Mahler’s Eighth and that more or less sum up key aspects of this recording. First, from a purely sonic standpoint, it’s pretty spectacular, most demonstrably in the closing sections of both halves, the “Glory to the Father” especially, where the sound frame expands with such ease and amplitude that one wonders whether it can possibly carry on building, which it does. Tilson Thomas’s reading is always warm and spontaneous-sounding but its real strength lies in the way phrases connect so that what can sometimes seem, on certain versions, merely a series of episodes (specifically in the Symphony’s much longer second half) emerges very much “of a piece”. The rocky soundscape that opens Part 2 is wonderfully atmospheric though never at the expense of detail – again the recording delivers a very believable perspective – and Quinn Kelsey’s Pater Ecstaticus is one of the best-sung performances on the set, rather better than James Morris’s intense but wobbly Pater Profundis that follows on from it.

There’s that unforgettable passage just before the closing chorus arrives, at around 5'05" into track 11, where, flute, clarinet, harp and celesta set up an ethereal pathway for the resplendent journey’s end. And in this context it has been quite a journey, Tilson Thomas drawing more colour and variety (tonal and emotional) from the score than almost any of his rivals, the best of whom include the keenly attentive Michael Gielen on Hänssler and Leonard Bernstein’s breathlessly exciting Sony LSO version (with Donald McIntyre a superb Pater Profundis). Others claiming our attention include Abbado, Haitink and Chailly, all memorable in their very different ways, but with wonderful sound, superb playing and generally fine singing (soprano Erin Wall is exceptional) I would rate this new version among the top two or three.

Attitudes to the Tenth Symphony’s infinitely strange and at times deeply unsettling Adagio will depend largely on how you view the various performing versions of the whole work. If a completed Tenth is your chosen option, then the Adagio on its own won’t do. If, however, you view it as a movement that was bequeathed to us more or less intact, and forget about building a context, then Tilson Thomas’s probing performance is fairly eventful and deeply haunting, and – again – beautifully recorded.