The Brangwyn Hall acoustic lends a lovely overall warmth to any music, but this concert by the BBC National Orchestra of Wales under Brazilian conductor Roberto Minczuk was made up of two such totally different halves as to deny it proper integrity. There was, however, no lack of curiosity value.

Opening the evening, the Three Hungarian Sketches by triple Oscar-winning Miklós Rózsa sounded like a mishmash of film scores, even though they were composed in 1938, before Rózsa had set foot in Hollywood. The music teems with ideas, with echoes of Rimsky-Korsakov, Kodály and, in the brassy ending, incipient Bernstein. Nicholas Whiting delivered the cadenza-like violin solo with authority and the finale's rapid swirl had verve, but it didn't amount to enough.

A second curio – played after the interval and with the orchestra reduced in scale – was the overture to the opera Los Esclavos Felices, written by the early 19th-century composer Juan Crisóstomo de Arriaga when he was 13. Known as the Basque Mozart (he shared the latter's birthday and died even younger, when only 19), his story is of a shooting star burnt out early: the overture's felicity and ease of line certainly bore that out. Mozart's Jupiter Symphony, K551 in C major followed but, in Minczuk's hands, this pinnacle of the classical repertoire sounded strangely anodyne and genteel, and only really picked up in the more spirited finale.

By far the strongest performance was that of the Third Piano Concerto of Rózsa's Hungarian compatriot Béla Bartók, with Llyr Williams as soloist. Articulating the music's valedictory tone with his usual perception and acute sensibilities, Williams also deployed the pianistic detail with a vast range of expressive colour. It was exemplary.