Proms 24 and 25: BBC Proms: BBC SSO/ Runnicles/ BBC Singers/London Sinfonietta/Atherton

Musical time-travel can often spring surprises, but the three-hour experience represented by Proms 24 and 25 was a uniquely strange journey.

It began with Mahler’s Third Symphony, a hundred minutes of music which has always provoked debate as to how it should be listened to. Even Mahler himself couldn’t decide whether his audience should get their bearings by following his pointers for each movement – ‘Summer marches in’, ‘What the flowers of the meadow tell me’, etc – or whether they should simply let the flow carry them along, with the righteous glow of religious redemption as their final reward.

Conductor Donald Runnicles, interviewed before mounting the podium, insisted that this work was as gripping as any fictional page-turner, and his considerable achievement with the BBC Scottish Symphony Orchestra was to make it feel like that. In the opening movement he let the terrain gracefully reveal itself as a vast cornucopia of effects, before entrancing the ear with the nostalgically-classical minuet which followed. The trumpet solos answering each other across the auditorium created great beauty, but the work’s centre of gravity was mezzo-soprano Karen Cargill’s wonderful delivery of the song from ‘Also sprach Zarathustra’: singing so softly and with such poise that she might have been a statue, she made the earth stand still.

Then out went the Mahlerians, and in came the modernists for a bare-knuckle ride with Bach and Stravinsky, whose 53-year-old 12-note Latin cantata ‘Threni’ was due for its first-ever outing at the Proms. With David Atherton conducting the London Sinfonietta, and with the BBC Singers fronted by a distinguished line-up of soloists, no one could say this work didn’t get the best possible chance, but it still came across like a brave but failed experiment: faint echoes of Stravinsky’s neo-classical works and of his majestic ‘Oedipus Rex’ only served to underline its over-intellectualised sterility. Let it now rest in peace.

But we’d reached this extremity via a fascinating route, on which a popular Lutheran chorale was put through a series of variations first by Bach and then by Stravinsky. And the surprise was that Bach’s – as demonstrated on the organ by virtuoso Daniel Hyde - were infinitely more daring and outlandish than those of his twentieth-century successor.