The name of Birmingham continues to resound in the historic Rhineland city of Bonn, birthplace of Ludwig van Beethoven, a week after a complete cycle of the composer’s nine symphonies played by the CBSO under its much-loved music director Andris Nelsons at the annual Beethovenfest.

It was a shrewd move to programme these works chronologically on four consecutive evenings, and without any other music, whether by Beethoven or not, to distract us from this close-up scrutiny of the composer’s development.

There were things in this concentrated exposure which sprang out even to someone who has known and loved this music for well over half a century: the perceptible discarding of Haydn’s influence; the fearless expansion of the orchestra (not least an emancipation of the timpani, who become very much an expressive force throughout the entire gamut); an uncompromising manipulation of tonality, whether for structural, expressive or dynamic ends; and the sheer revelation that several of these masterpieces were actually conceived in pairs.

And it was Andris Nelsons’ direct honesty of approach which brought out all these facets as he drew performances of immense engagement from his brilliant players. “Top of their form” is too feeble a cliche to use. These musicians were on fire, and could only have performed like this under a conductor with Nelsons’ generosity of spirit and totally unselfconscious podium-style.

The bond Nelsons has developed with his players over the few but glorious years of his music directorship must surely be unique. Which other orchestra would tolerate gestures which would be totally over-the-top from charlatans, but for Nelsons deliver with immediate empathy? Which other conductor could rely on these musicians to respond to sweeping bird-like flutterings, a kick of the heel, a sudden body-stillness, a pugnaciously driving fist, a conspiratorial flick of an eyebrow?

These were also in fact visual aids to the audience, Bonn-burghers and some who had travelled from further afield, long used to their Beethoven performed in a certain kind of routine, orthodox manner, as possessive of their local boy as the good people of Elgarshire jealously are of theirs.

But here Nelsons opened their ears to the sheer astonishing range and power of this music, and they responded with unstoppable enthusiasm. The standing ovations had begun after the First Symphony, no less.

The venerable Beethovenhalle is not the most comfortable of acoustics to play in, nor to listen in, depending rather capriciously upon where you’re sitting. There is a strong lobby to replace it, but an equally strong lobby which celebrated its 55th birthday while the CBSO and I were there, anxious to preserve it as an example of immediate post-war architecture.

Certainly it’s not Symphony Hall. Norman Stinchcombe’s roundup review of the complete Beethoven cycle now currently going on here in Symphony Hall will appear next week, but here are a few stray comments on what I heard in Bonn a week ago.

The opening evening was a marathon for players and conductor, bringing Symphonies One, Two and Three, and what a journey that was. From the First Symphony, Nelsons emphasising its Haydnesque qualities of airy lightness as well as its new-boy cheekiness, through the Second, more heavy in portent, and with gloriously singing lower strings, and so to the amazing Third, this “Eroica” Symphony drawing from all concerned a simple dignity and an exhilarating sense of achievement.

So often merely skated-over and making up the numbers, Beethoven’s Fourth Symphony is in fact a disturbingly dark work despite its manic attempts at high spirits. Nelsons continually drew attention to these moments of musing mystery, making us, as well as the players, sit up, and this account, even in the face of stiff competition, was in fact my highlight of the cycle.

This second evening was completed with the Fifth, no mere token run through of the repertoire’s most clapped-out warhorse, but an interpretation which got to grips with all the implications of those famous opening four notes as they recur throughout. Such a pity that the Beethovenhalle’s stifling acoustic squashed the perky piccolo pipings I know Andrew Lane was making in the finale.

Nelsons took us on a genuine journey towards terror and solace in his interpretation of the Sixth Symphony on the third evening. This “Pastoral” had a continually brooding sense of tension underlying these expressions of country life, exploding eventually in a storm of genuine ferocity which at last dissolved into a grateful balm bringing tears to the eyes.

Then all the storm’s energy was transmuted into the vigour which underpins the amazing Seventh Symphony, the players (strings in particular) working their socks off, and looking exhausted both physically and emotionally by the bat-out-of-hell end.

The final evening brought Beethoven’s apparent favourite, his Eighth Symphony, which he described as “die Kleine”, with Nelsons unleashing a gleeful torrent of dynamic and tonal clashes, and cellist Jesper Svedberg heroic in his busy cafe-trio solos.

So at last we came to the massive Ninth Symphony, Nelsons welding all its abrupt cosmic outbursts into a persuasively unified whole, but one in which Beethoven needed the arrival of vocalists to clinch matters. The solo quartet were appropriately operatic, but it was the amazing CBSO Chorus (for all they were standing behind what seemed to be football-terrace crush-barriers) who really stole the show.

Singing from memory, they projected with diction superlative even for them (the crucial words “Bruder” and “Welt” came through so proudly every time), and were fearless in the way they coped with Beethoven’s cruel vocal writing.

What Andris Nelsons and the CBSO achieved at the Bonn Beethovenfest was something beyond special. The Boston Symphony Orchestra has much to emulate.

* Andris Nelsons and the CBSO perform Beethoven’s Symphonies 4 and 5 (September 18, 2.15pm); 6 and 7 (September 20, 7pm); 8 and 9 (September 21, 7pm). All at Symphony Hall, details on 0121 780 3333.