This all-Nordic programme, performed by the excellent Estonian Festival Orchestra under one of the most admired conductors of the day, Paavo Järvi, had long promised to be one of this season’s special Proms. And in many ways it turned out that way, with a gripping performance of Arvo Pärt’s third symphony to begin and a beautifully played Sibelius’s Fifth to finish – its climax expertly held back by Järvi until the closing page.

The problem with the evening came with Khatia Buniatishvili’s account of the Grieg piano concerto in between the two symphonies. There has never been any question that Buniatishvili has technique to spare, and the fluid touch she adopted in the first movement emphasised the debts that Grieg owed to Schumann’s concerto. Yet with her playing there is always a “but”, and there was a mounting sense that Grieg’s voice was being sacrificed to Buniatishvili’s technique and keyboard theatricality. That fear became flesh in the final movement, which Buniatishvili seemed intent on playing as fast as possible. When she returned to play the world’s slowest and least idiomatic performance of Debussy’s Clair de Lune as an encore, it triggered, for me, that most unexpected of concert hall emotions – anger.

The Estonians had begun imposingly, sculpting the austerely ritualised 1971 symphony, with its roots in Gregorian chant, through which Pärt found his way to the more restrained later style that has become his trademark. Järvi’s control was clear and benign, and his trumpet, timpani and bassoon soloists stood out. The performance took place in the presence of the composer himself, and no one present will easily forget the way how, after taking his bow, the bearded 82-year-old sprinted back up the steps and away from the limelight like a man half his age.

• Available on BBC iPlayer.

• The BBC Proms continue until 8 September.