A concert in a carpark. It's certainly a novel way to experience live classical music, orchestra and audience gathered on Level 8 of a 1980s brutalist hulk of concrete, an ex-supermarket multi-storey carpark in Peckham. The traditional rules of engagement of classical music are more relaxed in this unusual setting. Audience are as committed as the musicians, who are dressed casually, but complaints about extraneous noise or inappropriate applause are rendered redundant, for the music is regularly suffused with the sounds of south London – rattling trains and honking traffic on Peckham Rye. The acoustic in this uncompromisingly stark urban venue is surprisingly good: the low ceilings amplify and intensify the sound, and the close proximity of orchestra to audience create a connection which makes the concert experience immediate and engaging.

The Proms first ventured to the carpark in Peckham in 2016 for a gloriously spine-tingling performance of music by Steve Reich. This year Johann (Sebastian Bach) met John (Adams) with a new work by Kate Whitley, co-founder of the Multi-Story Orchestra, interposed between them.

John Adams’ gigantic, absorbing Harmonielehre was the central work of the concert. A symphony in everything but name, this three-movement work takes its title from Schoenberg’s textbook on harmony, and in it Adams pays homage to the monumental works and rich romanticism of Mahler, Wagner, Sibelius and pre-atonal Schoenberg. Rejecting the more rigid minimalism of his compatriots Philip Glass and Steve Reich, Adams’ work fuses the familiar elements of minimalism – spooling motifs, complex rhythms, shifting time signatures – with the opulence of fin de siècle romanticism: thus the second movement, for example, does not directly quote from the Adagio of Mahler’s Tenth Symphony, but rather is a palimpsest, recalling with unfolding pain the earlier work, its rich textures and haunting melodies interwoven with Adam’s distinct use of sparkling percussion and hovering strings. From the booming, powerfully attention-grabbing repeated chords and propulsive energy of the first movement to the third movement, which unfolds like the sunrise opening prelude of Schoenberg’s Gurrelieder before building in intensity to an astonishing, emphatic blaze of sound, this was a performance which enthralled, the sounds of the city absorbed into Multi-Story Orchestra’s full-bodied surround sound.

Kate Whitley’s I Am I Say was written in 2016 for local schoolchildren and was performed by the Multi-Story Youth Choir, a wonderful group of young voices whose clear diction presented the music’s forthright message of hope and anger. Organised in three parts, this bold, energetic and empowering work is a heartfelt plea to wake up and care for the world around us. The orchestra and young singers were joined by soloists Ruby Hughes (soprano) and Michael Sumuel (bass-baritone) who both sang with elegance and clarity. Built on subtle repeated motifs, the music ebbed and swelled to fill the carpark concert space with a rousing and expressive final section.

A wake up call of a different kind opened the concert: Bach’s beautiful chorale prelude Wachet Auf, ruft uns die Stimme (Sleepers Awake!), orchestrated by Sir Granville Bantock, its tender and meltingly familiar melody played with an enveloping warmth, infused with the unmistakable sounds of the big city.

The venue may be unusual, but there's nothing novel about the Multi-Story Orchestra's approach. This was fully committed playing and proof that you can hold a concert anywhere, provided the musicians and the music are of the highest quality.