It was perhaps the only concert in the Wigmore’s history – and certainly the only one for much of the audience – where every piece of music was composed by an 11-year-old. But, of course, this was no ordinary 11-year-old.

Classical Opera (soon to be known as the Mozartists) are celebrating the maestro by presenting 250 years of Mozart, chronicling his short but prolific life year by year. Concerts began in 2015, with a nod to the young prodigy’s childhood visit to London, and will end in 2041. Tonight’s concert, however, is the first of the series to play music by the composer alone. Although with this, a small caveat: the keyboard concertos of 1767, tonight fronted by harpsichorist Kristian Bezuidenhout along with the Orchestra of Classical Opera under the baton of Ian Page, were not actually wholly composed by the young man himself. Instead, they have been granted the name “pasticcio” concertos, in the original meaning of the word – the sonata movements they encompass are from existing works by German composers the Mozart family encountered on their Europe tour. Put simply; almost everything Kristian Bezuidenhout played was by the orginal composers, and everything the orchestra played was composed by the prodigy.

It’s clear who gets the better half of the deal. There’s a certain charm to a programme that celebrates or homages those composers, almost all of whom are now fading into obscurity, that made up the rich tapestry of music and classical culture that must surely have both inspired the young Mozart and provided him with a canvas on which to excel. Many of the concertos – which tonight consisted of K.37, 39, 40 and 41 – were created as exercises set by Mozart’s father Leopold, and although they lack the brilliance and energy of his later, more mature works, many of the string passages and flashes of woodwind writing show an energy and creativity that is lacking in their grounding sonatas. This is not Mozart at his finest – but the gulf between his sections and the virtually unchanged sonatas from his contemporaries is obvious.

It is a gulf that Bezuidenhout does his best to breach. Opening with Keyboard Concerto no. 1 in F major, his mellifluous, liquid runs countered on the whole well with the heartier, more vibrant string sections. It took a little while for the delicacy of the harpsichord to battle against this vigour; initial subtlety was, unfortunately, lost, and initial cadenzas felt rushed and lacking pathos.

But these were teething problems; by the time Bezuidenhout introduced the “Allegro spiritoso”, both harpsichord and accompaniment had settled into a glorious conversational balance. Both parried the other with joie de vivre: Raupach’s original sonata lends itself well to a wonderful counter-balance of courtly swagger and poise. Sweet playing enhanced Schobert’s original “Andante staccato” from his Sonata Op.17, no. 2, which was a prime example of where Mozart’s accompaniment passages are marked with a lightness and vibrancy that, despite Bezuidenhout’s best efforts, were unsurpassed by the original writing.

Flashes of brilliance marked the concertos following the interval: sublime oboe soared over swathes of Keyboard Concerto no. 3 in D major, and Bezuidenhout’s cadenzas were as flamboyant and sparkling as his first concerto’s were hesitant. But it was the final concerto (no 4. in G major, based on Honauer’s first published sonata and the middle movement of Raupach’s previously copied sonata) that felt the most steady. The harpsichord, here, was not really the star of the show: instead, each accompaniment part played its role in a layered texture that was beautifully balanced and tempered. This was exciting playing.

Even for the most ardent Mozart lover, a full concert of experimental concertos could feel heavy; the inclusion of two arias, composed in the same year, with acclaimed soprano Soraya Mafi was both refreshing and well-needed. Granted, neither aria in itself is exactly glittering. Mozart’s writing at 11, however accomplished, lacks the drama and vibrancy which is so evident in his later works – especially for voice. But this is where Mafi came in to her own: given fairly sycophantic and weak recit to work with in A Berenice e Vologeso sposi… her clear, bright tone rang through each phrase with ease, and the aria itself – “Sol nascente in questo giorno” – ran like strings of pearls. There’s a childlike charm to Mafi’s clear excitement at performing, and this suited these early arias well. “Ein ergrimmter Löwe brüllet” from Die Schuldigkeit des ersten Gebots was slightly less impressive, lacking playfulness throughout, although retaining Mafi’s earlier lustre in its cadenzas.

The difficulty performers and patrons both faced was that, despite the occasional brilliant moment and some truly stellar playing and singing, these are not imminently exciting works. What they do highlight, however, is the huge melting pot of talent flourishing in 1767 to which Mozart – and classical music in general – owes a great deal.