Dvořák never stood a chance. There’s nothing inherently wrong or inadequate about his Serenade for Strings, yet in the context of this particular concert, it could hardly have felt more trivial. Notwithstanding one or two moments of scrappy coordination in its more rhythmic passages, the City of Birmingham Symphony Orchestra’s rendition of the work was crisp and light, turning the opening movement into an amuse-bouche and even channelling an exuberant, Mozartean playfulness in the Scherzo. Dvořák’s beguilingly mercurial approach to structure was prominent throughout, though in this reading wasn’t wholly convincing, lending the work a fickle attitude in which Kazushi Ono and the orchestra were simply going along for the ride rather than making sense of it. The piece is somewhat let down by the final two movements, which are arguably too functional for their own good, and while the Finale amusingly suggested the composer almost taking the mickey out of his own ideas, in the wake of what followed Dvořák’s music diminished to the point of being an elegant palate cleanser.

It took a while to realise that the CBSO’s performance of Bartók’s Piano Concerto no. 1, with Jean-Efflam Bavouzet at the helm, was utterly perfect. Having wisely positioned the percussion and timpani on either side of the piano at the front of the stage – highlighting the “triple concerto” nature of the work – we were immediately plunged into the discombobulating weirdness of its soundworld, Ono’s hands twirling in circles as though the orchestra were a spinning top, Bavouzet seemingly indulging a stream of consciousness, improvising and vamping at the keyboard. But then the penny dropped. We generally associate the term “experimental” with music of the last 70-or-so years, yet what we were experiencing here was a transparent reminder of how much it applies to earlier music. The Symphony Hall stage had became a laboratory within which Bartók’s marvellously weird experiment played out. And not with much caution either: ideas presented on a whim, toyed with for a while and abruptly cast aside; the role of soloist inverted, often reduced to banging out motifs in the lowest register of the instrument; recklessly moving back and forth between subdued, even stupefied material and wild, entirely unexpected outbursts.

It’s surely not unreasonable to describe the work as an anti-concerto, yet while it took time to adjust to its almost wholesale redefinition of musical roles and conventions, the journey from acceptance to engagement to enthusiasm was an exponential one due to the unbridled zeal of Bavouzet and the CBSO. Playing without music, Bavouzet clearly adored performing the piece, so much so in fact that for an encore we were treated to a repeat of the entire last movement. He evidently didn’t want the electrified atmosphere of danger and delight to end, and the extended whoops and cheers from the audience testified that we felt exactly the same.

For the performance of Strauss’ Also sprach Zarathustra – the most incomprehensibly neglected of the composer’s tone poems – it was Kazushi Ono’s turn to do without music. His putting aside of the score, removing the barrier between himself and the orchestra, was mirrored in the way he effectively removed the barriers between Strauss’ complex sequence of episodes and the audience. Ono deftly avoided the trap of making the work’s over-performed opening a prepackaged climax, instead presenting it as something nascent: music being spectacularly born, overflowing with vibrancy and life.

The fluid way Strauss explores his ideas can be perceived as an open invitation for conductors to treat both the structure and the material as if they were suggestions rather than something definitive. Ono’s approach was a well-judged blend of fastidiousness with just a hint of incaution, seeking less to interpret the music than simply allowing it to speak on its own terms. This produced some surprises, laying bare the intimidating muscularity and occasional anger manifesting within Strauss’ material, made all the more potent by their proximity to such heart-stoppingly rapturous melodies (among the composer’s finest). Nowhere – neither in the tender lyricism nor the enormous climaxes – was the CBSO allowed to linger, another striking effect of this being the remarkable “Von der Wissenschaft” fugue, which was here revealed for what it really is: a slow-burning process gradually taking effect and taking hold, spreading and expanding.

The philosophical dimensions of Also sprach Zarathustra – Strauss taking inspiration from Friedrich Nietzsche’s book of the same name – are undeniably and fearlessly convoluted, yet without denying their scope or importance, Ono rendered them clear and approachable. Ending the concert on such a profound note of uncertainty – the work closes with nothing but questions, worlds away from the unambiguous triumph of the start – was the ideal end to a concert that achieved the very best of which music is capable, provoking us to question what we thought we knew.