Daniel Barenboim’s cycle of Beethoven’s piano sonatas given in eight recitals at the Festival Hall came to an emotional end last Sunday afternoon with the last work, Op 111 in C minor, after which the capacity audience instantly rose to its feet. As an audience phenomenon, these concerts have been unparalleled in London in recent times. It wasn’t just that the hall was sold out every time, with people spilling onto the platform behind and beside the pianist, and a throng in the foyer for returns, but that the audience was so manifestly attentive to the music (few noises off) and seemed a wider cross section of the public than is usual for classical concerts.

Celebrities and youngsters swelled the ranks of stalwart grey-heads, and everyone seemed to glow a little, as if touched by a sense of history. The concerts will undoubtedly be talked about for years. As a physical and intellectual feat – memorising the music and maintaining the stamina to get through the cycle – what Barenboim achieved was impressive enough, but we were given interpretations to stand with the greatest, reimaginings of familiar music that never failed to surprise and delight.

Like most of the other programmes, the last comprised works from Beethoven’s early, middle and late phases, and was a satisfying whole, not a scholarly exercise. (Giving the cycle chronologically is interesting, but Barenboim’s way is more artistic.) He began with a marvellous account of the not-too-often-heard, brief but beguiling E major sonata, Op 14, No 1, and lent the ascending chromatic scale that is the allegro’s curious second subject a witty glint that had me wondering, here and when the passage recurred, whether Beethoven wasn’t flirting, in the nicest possible way, with atonality.

To the grand E flat sonata, Op 7, Barenboim brought his most vivid orchestral palette. He made it seem a template for the Eroica symphony in the same key. Drama was rife. He sat bolt upright (nearly leaving his chair) for a climax at the end of the allegro molto, and pounded the repeated group of six fortissimo chords in the largo with a venom. Then the third movement began with the melting limpidity in which he also excels. Indeed, it was his mezzo-piano playing, with its subtly pedalled diversity of shades and uncanny carrying power, that was one of the revelations of the series.

Astonishingly, Barenboim’s playing became even more compelling and brilliant as the concerts went on. One could have forgiven a slackening of energy as the end approached, but the fascinating two-movement sonata in F, Op 54, with its fierce staccato octaves in the first movement and the perpetuum mobile semiquavers of the second, was done with an immaculate virtuosity that itself seemed to generate the strength needed to mount the summit of that other two-movement sonata, Op 111, with its sublime adagio finale. In fact, he had strength to spare.

What a musician this is. One who has scaled equivalent heights as a conductor. During an RFH forum about artistic leadership (in which he was joined by Peter Hall and Tony Benn), he scoffed at pianists who think they can conduct, but he is the great exception. He has conducted the Ring at Bayreuth. He is music director of the Berlin Staatsoper. He premieres formidable orchestral and operatic scores by Birtwistle and Carter. There is only one pianist-conductor, I think, to whom one can compare him, a figure he resembles in quite a few ways, and that is Franz Liszt.

A couple of hours after the cycle was completed, the Southbank’s other grand project, From the Canyons to the Stars, a centenary exploration of Messiaen’s oeuvre, with months to run, continued at Queen Elizabeth Hall. The London Sinfonietta was conducted by Peter Eötvös in one of Messiaen’s most spectacular pieces, the ritual meditation on last things, Et exspecto resurrectionem mortuorum, scored for a large, loud band of wind and percussion.

Like most Messiaen, it is a cyclic juxtaposition of a few blocklike elements, but it has a stark and savage power surpassed by none of his works. In part, this comes down to the size of the tam-tams used: the largest has an impact fit to burst the eardrums. But Messiaen’s austere integrity burns through every bar. The two-minute, light-dimmed pauses between movements did not seem pretentious.

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