On Saturday evening, the Amsterdam Sinfonietta with soloist Ronald Brautigam presented a splendidly varied programme including pieces by Webern, Mozart and Bach.

The Sinfonietta began their programme with a thrilling adaptation of Webern’s Langsamer Satz, an early neo-Romantic piece originally written for string quartet. The adaptation the Sinfonietta played artfully alternated between the ensemble’s full orchestral forces and the original chamber setting. Within the chamber setting, the passionate lyricism of principal violist Daniel Bard was particularly memorable. Through the Webern, the Sinfonietta showed its finest qualities including an impressive unity of gesture, a vibrant sense of colour, a meticulous attention to detail, and a remarkable dynamic range. As an ensemble without a silent conductor, the Sinfonietta generates a thrilling energy in performance as every player enters a state of heightened awareness of his or her own musical function. As a result of their chamber approach, their performance of the Webern was stylish and engaging.

Ronald Brautigam played a historic fortepiano made in Sicily in around 1815. The fortepiano has a less homogenous sound, a softer voice and very different expressive qualities than a typical concert grand. Within the concerti, balance between fortepiano’s quieter voice and the Sinfonietta’s full complement was occasionally problematic. The Sinfonietta’s concerto tuttis were sometimes painted in broader strokes than their more lovingly illustrated Webern.

Brautigam’s performance of Mozart’s Concerto no. 18 in B flat major was impeccable. His interpretation of the first movement (Allegro vivace) struck a fine balance between rhetorical flair and graceful filigree, and his continuo shaped the orchestral tutti sections clearly. His execution of the passagework was elegantly understated, more conversational than virtuosic. His cadenza was appropriately sparkling and delightfully unpredictable. The Andante un poco sostenuto is an agitated theme and variations in G minor in which Mozart’s soloist pleads ardently against the implacable orchestral furies. In the solo sections, Brautigam’s playing evoked tenderness, fragility, bitterness and grief, as he declaimed every note with a refined variety of articulation and rhythmic flexibility. Brautigam began the bright Allegro vivace in a sprightly tempo which the Sinfonietta enthusiastically answered with exuberant dance rhythms. Brautigam’s mischievous Eingangs (improvisatory passages leading into a restatement of a theme) complemented the mercurial character of the final movement perfectly.

From the opening tutti of the proto-Romantic Concerto in F minor (now most commonly thought to be by J.C. Bach), the Sinfonietta, supported by Brautigam’s continuo, evoked the furious character of the Allegro ma non troppo with tremendous urgency. Brautigam’s solo passages were wild and exciting; his cadenza was forceful and succinct. The ensemble adopted an unexpectedly brisk tempo in the heart-rending Molto adagio, emphasizing the passionate character of the movement. Brautigam’s solo passages were ardent and eloquent. The Sinfonietta began Bach’s frenetic Presto at a thrillingly quick pace. They sculpted the ritornelli deftly, emphasizing Bach’s unpredictable harmonic progressions and jaggedly emphatic unison passages. Brautigam’s passagework, often in blisteringly fast sextuplets, was expertly executed.

The final piece on the programme was Mozart’s Symphony no. 40 in G minor, in the original 1788 setting without clarinets. The first movement (Molto allegro) was performed gracefully, more sadly than sternly. The intensely chromatic and contrapuntal development section of the first movement was played with ardour and force. The middle two movements were truly extraordinary. Warmly coloured by the violas and horns, the Andante displayed a beautiful unity in expression between the wind and string sections, and the Sinfonietta’s crystal clear textures in this movement were stunning. The Sinfonietta’s Menuetto was forceful and harsh, performed with a groovy and sinister dance character. In the Finale (Allegro assai), the ensemble strongly emphasized a passage in the development section in which Mozart writes a nearly complete twelve-tone row in harsh octaves, only omitting the tonic and dominant of G minor. Though Webern’s Langsamer Satz is one of his early pieces written in a neo-Romantic idiom, this emphasis of Mozart’s tone row recalled the first piece on the Sinfonietta’s programme with associations of Webern’s signature serialism. The Sinfonietta’s short and sweet encore provided an elegant close to an excellent evening of music.