It must be a strange feeling, sitting down to play a short work while surrounded by empty chairs waiting for a big second half symphony. Tonight Steven Osborne and the modest proportions of Mozart’s orchestra were given the task of invigorating the Piano Concerto no. 19 and avoiding an almost inevitable feeling of it being a pre-Mahler apéritif.

This concerto was the sixth composed in 1784 alone, during a period in which the composer found himself at the height of popularity in Vienna, his life hectic with concerts, writing and teaching. This duality of confident success and busyness was perfectly captured by the BBC Philharmonic and Osborne, the two interacting so closely that Juanjo Mena seemed redundant at times, there simply to nod and guide. Osborne was a humble accompanist as well as soloist; when accompanying a woodwind melody, his gaze would remain fixed towards them, adjusting his playing to suit theirs. In his own playing there was a lightness of touch, particularly in his cadenza staccato, which was complemented by crisp and clear string playing. The third movement felt almost boisterous, propelled by prominent horns, but it remained serious, not threatening to become comic. Opposing the cellos and first violins in seating was also a nice touch, allowing cross-stage conversations. Osborne found subtle rubato in the warmly lyrical slow movement, and his Beethoven Bagatelle encore seemed a pleasant afterthought to this. This was a very enjoyable performance in its own right, significantly adding to rather than simply lengthening the concert.

The orchestra returned more than double in size for Mahler. Like the Mozart, the Symphony no. 5 was composed at a time of personal contentment, Mahler having recently married Alma Schindler, and this sunniness appears chiefly in the latter parts of this five-movement, three-part symphony. This being Mahler, though, the victory is hard-won: the first two movements are interspersed with echoes of childhood trauma (Mahler lost six of his twelve siblings to childhood death), wild outbursts and despairing gloom before the emergence of a heroic brass chorale in the second movement, later to reappear at the end of the symphony.

The principal trumpet has an enormous role in Mahler 5, tonight carried off very impressively by Jon Holland. His opening solo, one of the most famous in the repertoire, was unhurried, triplets individually tongued and avoiding over-confident displays of boldness. The solo grew over the first bars and was answered by full-blooded orchestra. The tutti passages showed a driving intensity in the first two movements, violently explosive in the second and in stark contrast to the very gentle funeral march of the first. Mena handled the transitions from meditative lower strings to furious tutti very well, and the brass chorale felt richly deserved, although he might have saved something of this for its reappearance in the fifth movement. As a mediator between Parts 1 and 3, the third movement (Scherzo) was refreshing and natural, most enjoyably so in pianissimo pizzicato waltzes which accelerated gently into energised dances.

The Adagietto for strings and harp is possibly Mahler’s most famous creation. Malcolm Hayes’ programme note warns against turning this movement, marked “Sehr langsam”, into a “funereal dirge”; Mena led an extremely slow performance without threatening to mourn or wallow, suggesting instead the composer’s love for Alma. The strings played with rich legato and soft, slow movements between notes, travelling from pianissimo, via impassioned emotion, to an even quieter close in a wonderfully eloquent performance. The fifth movement was attacked without pause, the horn call feeling almost rude. The following wind solos, though, echoed and embellished the natural feel of the Scherzo and blossomed into a light dance. The intensity crept up through the movement while maintaining the dance, and the ascent into the chorale was magnificent. Mena pushed onwards through the last minute, accelerating in the closing bars to a joyful conclusion. The concert was recorded for future radio broadcast, and it will be well worth hearing.