For inspired craziness no 18th-century composer, surely, can touch Emanuel Bach. When Baron van Swieten, of Haydn Creation fame, commissioned these six string symphonies in 1773, he encouraged the composer’s imagination to run amok. It duly did in works that, even by Emanuel’s standards, seem like a calculated assault on contemporary norms. Moments of galant euphony – say at the opening of No 6 in E – are tactlessly subverted by an explosive outburst or a swerve to a shock chord. Pushing CPE’s characteristic vein of soulful Empfindsamkeit to extremes, slow movements veer disconcertingly between song and speech. Disruption and disorientation, on every level, are the order of the day. Small wonder that this outré music, intended for a select circle of connoisseurs, never achieved wide circulation.

In each of these 10-minute symphonic volcanos Emanuel Bach tests the players’ corporate virtuosity to the limit, exactly as van Swieten had hoped. Led by violinist Alexander Janiczek, the strings of the Orchestra of the Eighteenth Century meet their technical challenges head-on. Animated by athletic bass lines, fast movements seethe and crackle with anarchic energy. Bach’s extreme dynamic contrasts and harmonic shocks are played for all their worth, yet amid the melee Janiczek always leaves space for expressive shaping. Violins are properly divided left and right, with vivid results in, say, the tumbling exchanges at the opening of No 4 or the antiphonal sparring in No 2’s finale.

Janiczek and his 24-strong band are also closely attuned to the inwardness and precarious lyricism of the slow movements. Never was the veneer of innocence more deceptive than in No 4’s Largo ed innocentemente. The Larghetto of No 5 is a rare instance of Bach allowing himself an (almost) uncompromised cantabile melody. The players phrase this with a vocal eloquence, and then beautifully float the chains of bittersweet suspensions.

Early allegiances can die hard, of course. The first recording to do these symphonies full justice, from Trevor Pinnock and The English Concert (Archiv, 10/80, 5/86), is well over 40 years old but still sounds as thrilling as ever. It’s more intimately scaled than this new version, with a more prominent harpsichord continuo (I’m not complaining). While tempos are often virtually identical (an exception is the Poco adagio of No 2, where Pinnock’s far slower performance is strangely haunting), Pinnock’s band sometimes lives that much more dangerously. But orchestra size apart, interpretative differences are often minimal. If any recording of this still-astonishing, unnerving music can give Pinnock a run for his money, it’s this new one.