At Amazon's current price, this has to be the bargain of the decade. Some 1247 minutes (and 14 seconds) of Beethoven solo piano music in magnificent performances: pretty much as complete as it gets, all for £21.80. Only Brautigam on BIS approaches this level of completion, but he performs on fortepiano; to give you an idea, Tirimo offers about 3 and a half hours more music than Brendel, and about 3 hours more than Buchbinder in their "complete" traversals. What's more, Tirimo performs with a uniform level of excellence: he lavishes as much care on  the 1783 Dressler Variations (the first piece we hear on this odyssey) as he does the mightier of the Sonatas. And what a treasure trove this box is: remember that with the 35 Sonatas - you read that right - you only get 55% of Beethoven's solo piano output.

With the likes of complete Debussy piano music and complete Schubert Sonatas behind him, there's clearly a completist side to this pianist. One aspect of the set that shines therough is Tirimo's tonal palette , orchestral in scope (here he is in accord with Brendel, who has written most eloquently on this very subject).

So why 35 Sonatas? Tirimo includes the three so-called 'Kurfürstin' Sonatas of 1782/3, with the label 'WoO' 47 (WoO stands for Werk ohne Opus, or work without opus number). Listen to the first movement of the second, F Minor sonata, its opening introduction surprisingly profound.

PIano Sonata in F minor, WoO 47/2 (i)

Then there's the Two Preludes of Op. 39 - how many pianists even have heard of them? And yet what is remarkable is that each one cycles through the complete set of sharp and flat keys, with No. 2 flexing its muscles and even doing it twice. It's a bit dizzying harmonically, as you might imagine, but absolutely fascinating. In the second Prelude, Beethoven achieves his double-lap feat in less than two and a half minutes. The result is surprisingly beautiful:

Prelude "in" C major, Op. 39/2

Perhaps it is the revelations of the more experimental side of Beethoven that round out our picture of the composer. In conversation once, both Tirimo and myself were in complete agreement as to the majesty and wonder provided by the Fantasy in G minor, Op. 77, a piece that really does deserve to get out more, and one that poses unique interpretative problems as it is just so gestural - this, from Beethoven, "the great structuralist"! Tirimo rightly has described this as "a masterpiece of the first rank":

Fantasy in G minor, Op. 77

There's always the thorny question of repeats in Beethoven. Such a topic sounds academic, until you listen to Tirimo's performance of the famous 'Pathétique' Sonata, where he repeats back to the slow introducton, not to the Allegro as is usually heard. The effect is arresting and comes across, frankly, as a stroke of genius on Beethoven's part:

PIano Sonata in C minor, Op. 13, 'Pathétique' (i)

It is perhaps right that in a blog entitled Classical Explorer, we concentrate on the lesser-known works, and I have reported on the more famous pieces elsewhere (most notably in an extended review in the American journal Fanfare). But let's move from one end of Beethoven's output to the other: the almighty 'Hammerklavier' in a performance of the utmost command. This is one of the greatest of all piano sonatas, and Tirimo accords it its due; his technique is matchless.

"Hammerklavier" (i)

Pointers towards something else lesser-known but delectable? Try the two Rondos, Op. 51, or the Variations on 'Une fièvre brûlante' from Grétry's Richard, Coeur de Lion (itself a fabulous opera, by the way: see my review of the fairly recent  Versailles performance here and my interview with that performance's conductor, Hervé Niquet, here).

There's no doubt that this is a major set, and quite possibly Martino Tirimo's magnum opus; and at the price, it is surely unmissable.