How many times have you heard the Eroica? Among the greatest of Beethoven’s many masterpieces, it stands in testament both to his towering ambition and, with the self-appointed emperor Napoleon’s name scratched in rage from the front page, the iconoclastic, revolutionary spirit that so enamours us to Beethoven to this day. It was strange, then, that I found myself tiring of it during the second of the San Francisco Symphony’s two Proms, directed by Michael Tilson Thomas.

There were fine details, but the whole sounded tired and lacking in energy or drive. Stranger still that it followed excoriating performances of Decoration Day, from Ives’s symphony “New England Holidays” and Bartók’s Second Piano Concerto, with the effortless virtuosity of Yuja Wang. As with their first Prom, the energy and precision that drove the first half to the very heights of musical performance seemed lost in the ‘big piece’; with Mahler in the first Prom and Beethoven in this one, these core repertory pieces seemed over-familiar, lacking the inspiration of constant rediscovery that makes great performances great.

Bartók’s music, changing restlessly from moment to moment, imbued with the metrical irregularity and unpredictability that characterises the folksongs the composer so cherished, thrives on the restless, wide-eyed energy of performers. There are few better for this repertoire than the young Chinese firebrand Yuja Wang, whose blend of vigour and absolutely unbreakable technique mean the formidable octave melodies and fingerwork of Bartók’s Second Piano Concerto pose little challenge.

From the motoric opening movement, set for piano, brass, wind, and percussion, Wang was in her element; shifting rhythmic emphases were brought out with a painstaking and punishing approach to the piano part’s accents. The epic slow movement had a doleful quality, and the finale was launched with madcap abandon. None of this would have been possible without the brilliance of the San Francisco players; the brass and wind were punchy, polished and precise, the slow movement’s strings chillingly ethereal. If the acoustic meant the piano’s upper range was slightly lost, the power coming from the bass end more than made up for it.

Decoration Day is one of those classic Ivesian constructions bringing together great American songs with the height of Modernist technique. Building steadily, a slow hymn gradually gives way to a bombastic marching band which tramples the hall, before a final intimation of the hymn, made more moving for its stoicism in the face of this pomp, closes the piece contemplatively. Tilson Thomas brought out well the earnestness of the song’s melody, emphasising the flow of the melody and the interplay of instruments well. Balancing the climax well, he managed to avoid the effect of over-management of the Sousa-on-steroids march, the trombones’ roaring never covering the strings or the chromatic lines in the horns and wind.

Beethoven’s textures didn’t fare quite so well. Part of this is without a doubt due to the use of rotary-valve trumpets, a staple of German and Austrian orchestras which produce a huge, round sound. This clashed with the slightly thin but unerringly precise sound of the strings, from which Tilson Thomas drew very clear articulation, though sometimes at the expense of the long line. Moreover, the wind were frequently covered by the force of the brass; not always desirable when the trumpets of Beethoven’s day could play so few notes.

Climaxes were, admittedly, glorious and the tutti sound filled the hall. However, tempi were often on the slow side, robbing the Scherzo of Beethoven’s characteristic elfin bounce and life; the funeral march felt bogged down by simply too much pathos, and the slow variations in the finale were so inflexible that the poor horns’ grand statement of the melody felt overwrought. Inflexibility was the key problem here; the first movement’s horrendous dissonances were passed over like any other cadences, blunting the lethal blades that threaten to bring down Beethoven’s hero. The finale lacked wit, the opening taken at a hair-raising speed, the main melody lacking grace, and the cheeky syncopations that mark the beginning of the journey to light robbed of their sunny sense of hope.

Tilson Thomas’ orchestra was, though, in just as fine a form as it had been the night before, with beautiful solos abounding. Principal horn Robert Ward was faultless from start to finish, with the three horns sounding beautifully in the hunting Trio of the Scherzo, and the clarinet entries towards the end of the funeral march were ghostly, and magically beautiful. An encore of Brahms’s Hungarian Dance no. 10 returned the orchestra to energetic form, reminding us of the searing heat of the Bartók and the nostalgic phantasmagoria of Ives’ ludicrous march. It’s just a shame that the energy levels dropped so notably for the Beethoven, with no sense of rediscovery or, ultimately, joy in this most joyful music.