Following on from the Contemporary Chamber Works concert of the LSO Futures series, François-Xavier Roth was back less than an hour later with the Symphonic Sound Worlds programme. This formed the second part of his investigation into the nature of the orchestra, its traditional forms and generic makeup. The title “Symphonic Sound Worlds” hints not only at the expansion of orchestral sounds, but also at the effects of these sounds upon the more general “worlds” within which they are deployed. For centuries the symphony could be identified by its formal construction: it was a large-scale orchestral work in which individual movements had particular harmonic and structural functions. However, the augmentation of these parameters brought with it satellite genres and even intrusions upon the symphony itself. The works selected for this second concert – Anton Webern’s Passacaglia (1908), Pierre Boulez’s Notations for orchestra (1978–), the Panufnik Variations (2013) featuring composers associated with the Panufnik Composers Scheme and Claude Debussy’s La mer (1903–05) – bore the vestiges of such a tradition in different ways.

Roth’s decision to commence the concert with Webern’s Passacaglia for orchestra was an imaginative one. The variations revolving around the ghost of a 17th-century bass line are a far cry from the serialist rigour of Webern’s later works. Nonetheless, this was the composer’s first published piece and remains just as successful as his mature contributions. Interestingly, Webern’s fascination with old forms persisted into his later years and informed such works as the Symphony (1928), the Concerto for Nine Instruments (1934) and the String Quartet (1937–38). An aura of historical sound was established across this performance, with the London Symphony Orchestra players relishing swells of dissonance and their eerie recession into the background.

Boulez’s Notations was possibly the highlight of the entire concert. Derived from the Douze Notations for piano (1945), this extraordinary orchestral work has undergone several permutations. Initially, Boulez created a transcribed version for chamber orchestra in 1946, but did not acknowledge this effort as a part of his output. It was only in 1977 that he revisited the material and decided to extend its content. The original piano pieces, minute in their stature, contain deftly chiseled musical profiles indebted to the serialism of Schoenberg and Webern, along with covert glances at Messiaenic harmony. The five orchestral versions performed in this series were rife with instrumental colour, harmonic deviation, extended polyphony and gestural inflection. It was simply staggering that so much fresh material had been drawn from such a crystallized suite. Roth’s leadership was astute, allowing the performers to engage in frenetic dialogues while feeding the rigidity latent in this music. Five separate scores constructed on an almost biblical scale were an effective salute to the aphoristic quality of this music.

With its emphasis on discovery and investigation, the programme created a sympathetic space in which new works could be listened to. The Panufnik Variations certainly benefitted from this context. Supervised by composer Colin Matthews, nine composers associated with the LSO Panufnik Scheme were invited to build a set of variations based on a theme by the Polish composer Andrzej Panufnik (to whom the scheme is dedicated). It was a task that could have potentially produced some confused results, but was addressed with care by this team. Max de Wardener, Evis Sammoutis, Christopher Mayo, Toby Young, Elizabeth Winters, Larry Goves, Raymond Yiu, Anjula Semmens and Edmund Finnis all created music that wrestled with the theme in resourceful ways. Perhaps the most ingenious responses came from Max de Wardener, Raymond Yiu and Edmund Finnis. Wardener’s capacity to imbue the most chaotic and erudite of orchestral fragments with meaning made for a perceptive opening variation, while Yiu’s sagacious fusions of Chinese and jazz idioms were full of charm and currency. The final variation by Finnis was brimming with erotic energy as it moved through diaphanous forms and was therefore a graceful precursor to Debussy’s La mer.

As with Stravinsky’s Symphonies of Wind Instruments in the first concert of the evening, Debussy was careful to avoid the loaded term “symphony” for his composition La mer. Instead it is subtitled “Three symphonic sketches”, a classification that also frees it from the parallel genre of “programme music”. Each movement has one descriptive prompt: “De l’aube à midi sur la mer” (“From Dawn to Noon on the Sea”), “Jeux de vagues” (“The Play of the Waves”) and “Dialogue du vent et de la mer” (“Dialogue of the Wind and the Sea”). Watching this performance was like experiencing the sea itself: the composer beckons the instruments to rush, sway, drip, spray and roar in an effervescent harmonic dialogue. However, the music is evocative of the sea on a level beyond predictable mimicry. The writer and composer Jean Barraqué describes Debussy’s composition as consisting of an “open” form, one of “sonorous becoming”. Indeed it is the elusive interplay between sensuality, eroticism and proposition that lies at the heart of this enigmatic work. These elements were beautifully defined by Roth and the LSO players and allowed La mer to shine majestically.