Leif Ove Andsnes, Royal Festival Hall, London

It's a brave pianist who makes Grieg the climax of a sequence taking in Bach and Beethoven. Leif Ove Andsnes upped the stakes further by championing Grieg's Ballade in G minor, which features in his current recordings and recital tours but is otherwise rarely heard. A sophisticated fusion of variation form, dance character and lyric tragedy, it emerged at the end of Andsnes's first half – or, at least, he was able to make us hear it – as a discovery to rank with Glenn Gould's championing of the equally wondrous Variations Chromatiques de Concert of Bizet.

The point is cumulative power. There's a theme kitted out with Grieg's captivatingly gloomy harmonies – so far, so typical – but it gets a gradually intensified workout that culminates in a linked series of concluding transformations, like a wild wake with a briefly resplendent peak and a return to the original gloom, several shades deeper.

Andsnes hung on to the pivotal moment, crashing octaves left suspended as the notes died away, until you realised that they are the same as the start of the theme, which he brought back with a poised perfection of phrasing and timing.

This recital was full of thought-through performances, yet the first half's appearance of being uphill all the way wasn't always to the advantage of other works. Andsnes is too musicianly to deliberately underplay Beethoven's Sonata "quasi una fantasia" in E flat, but his performance was constrained and watchful. Its best moments included the early sudden shifts of harmony, and the burgeoning climax of the Scherzo.

Four short pieces by Sibelius were beautifully understood in their balance of contradictory urges towards terseness and lyrical freedom, and diminished by their placing in the programme, especially when Andsnes segued into the Grieg, as though Sibelius's Barcarola were a prelude to it. Bach's E minor Toccata was unusually lyrical and playful, but with a determination in its final fugue.

Andsnes was again his own man in drawing from both books of Debussy's Préludes. Finely judged shades of tone and dynamics kept the performances alert and engaging, at their best in passages of quiet vivacity and brilliance.