Ivan Fischer is acquiring, if he hadn’t already, a reputation as one of the great musical mavericks alive today. Shortlisted for this year’s Gramophone Artist of the Year award, he has a track record for accessibility and great musical energy. Not surprisingly, the announcement that his ‘late-night’ Prom 64 with the Budapest Festival Orchestra would be ‘Audience Choice’ caused a flurry of excitement, even though it is just one of many unconventional turns of concert style taken this season. The intrigue of a surprise programme was as much a talking point as the performance itself; fortunately, Fischer proved that he can entice entertainment value and top quality playing from his orchestra at once.

This was probably one of the few variations on the conventional concert format guaranteed to please at least some of the audience. Attendees were given numbered slips and corresponding tickets. They were then entered into a raffle, tickets were drawn from a tuba’s bell by audience members, three lucky winners chose a next piece and a vote was taken for the ‘winner’. This was repeated until an hour or so had passed. With a list of 285 pieces, excerpts and movements to choose from, the programme was always going to be a strange and inimitable mongrel. But anyone expecting an over-worn mix of popular Classics, averagely sight-read, was in for a pleasant surprise.

Predictability was lessened by the fact that the music was not entirely audience choice. We were welcomed into the hall with a folk string group jamming at the edge of the stage. And then, as the actual concert progressed, there were gaps between choices being made and scores being distributed. In these gaps, not only did Fischer seize the opportunity to converse with his audience, but members of the orchestra gave entertaining mini-interludes. These were as diverse as a Transylvanian folk duo, an a capella human percussion quartet (more bottom-rapping and rhythmic clicking than you could shake a maraca at) and a tantalising didgeridoo performance.

The works which did make it to actual performance were exciting, technically challenging and sensitively played. True, lesser-performed composers such as Josef Lanner and Leroy Anderson did not receive their moment on stage, but there was no Mozart or Beethoven. Instead, the audience stuck to a largely Hungarian theme, voting in Kodaly’s Dances of Galata, Brahms’s Hungarian Dance No.1 and Bartok’s Romanian Folk Songs. We then finished with Berlioz’s Hungarian March from the Damnation of Faust, waltzing by Josef Strauss’s Music of the Spheres on the way.

But it was the breakneck speed of the overture to Mikhail Glinka’s opera Ruslan and Lyudmila that completely won over the audience. It summed up the vigour with which this versatile orchestra tackled the most rapid of bowings and the largest numbers of notes crammed onto the stave throughout every work, somehow managing to grin through it all. Most of these pieces required a certain amount of showmanship; even late at night, spectacle was clearly the audience’s priority rather than calm.

The populist nature of the concert probably annoyed some more conventional Prommers, as did the inevitable slackness of some string and woodwind entries and the tempi in general. But the unconventional and ambitious construction of the night’s programme as it evolved did not produce, as Fischer had warned in his written and spoken introduction, any major musical mistakes other than these unpolished edges. Quite the opposite; the standard was high in terms of interpretation and articulation. This juke-box style of performance does have its downside; the need to keep each ‘number’ on the selection list to a single movement means that the sustained musical and emotional balance of a complete symphony, opera or other large-scale work is impossible.

No-one was expecting this kind of calculated journey in the shorter late-night Prom, however. We were expecting a spontaneous and energetic set of musical highlights. And the Budapest Festival Orchestra delivered, responding whole-heartedly to the energy of Fischer. Their two BBC Proms appearances in one evening (the first featuring Liszt and Mahler) came at the end of a punishing summer. Four festivals, four European countries, and barely a week to go until their autumn commitments begin. But I have never seen an orchestra look less tired. The hundred-plus ensemble showed good humour and utter commitment throughout. The result was 75 minutes of amiable spoken and musical dialogue between musicians and audience, where cavalier conducting flourishes glossed over any imperfections and the majority appeared to go away smiling. For this reason the concert can be called an overwhelming success. For the Proms were designed to be the people’s concerts. Tonight’s embodied that idea to its core.