Highly regarded in the US – ‘one of the greatest living virtuosos ’ is typical of many effusive accolades – the American organist Paul Jacobs is virtually unknown in the UK, which probably explains the embarrassingly small audience for his Symphony Hall debut. Another reason might be that, despite his undoubted technical prowess and ability to play everything from memory, he is actually a very serious musician.

The programme on Friday, like his Town Hall recital earlier in the week, consisted entirely of core repertory. Here there were just two composers, Bach and, much more significantly, Reger who, as Jacobs rightly said, is still woefully neglected outside organ circles.

To illustrate his admiration for Reger – and Reger’s for Bach – he delivered an electrifying account of the Fantasy and Fugue on BACH (but did we really need to have the letters explained first?) that conveyed a maelstrom of emotions, even in quieter sections, and developed the fugue, with hands and feet going everywhere, into a raging behemoth of contrapuntal activity.

If not as hysterically impassioned, at least until its conclusion, Reger’s Variations and Fugue on an Original Theme was just as impressive and, at thirty minutes (it seemed far less) something of a musical odyssey. And what an engrossing journey it was, brilliantly undertaken by Jacobs, who fully exploited the instrument’s tonal resources, often by moving seamlessly mid-flight between manuals to create shifts in weight and colour.

Bach’s Trio Sonata in C sparkled with appropriate Baroque registration, although Jacobs’ use of the swell pedal probably offended purists, as did his accelerando at the end of the A minor Fugue BWV543, which he gave as an encore.