Lucerne Festival Strings/Fiedler Poltera, Goldsmiths' Hall, London

Raised on a dais amid the splendours of the Goldsmiths' Hall in Foster Lane, the 17 young players of the Lucerne Festival Strings were ardent and polished under their conductor, Achim Fiedler, for their appearance in the Swiss-themed City of London Festival.

They opened and closed with two of those crisply proficient string symphonies that Mendelssohn was already composing in his early teens – a curious mix of neo-baroque formality, lightness and dash. The one-movement Symphony for Strings No 10 in B minor opened gravely, but was soon scudding along with Mendelssohnian intentness, while the Andante of the Symphony for Strings No 9 in C major featured a mysterious walking fugato that foreshadow the "Pilgrims March" movement of the Italian Symphony, still a decade in the future.

The heart of the concert, however, was devoted to two works by the Swiss master Othmar Schoeck (1886-1957), less known in Britain than he deserves to be, but who made highly distinctive contributions to 20th-century opera and song.

The two late works we heard tended to look back at the romanticism of Schoeck's youth. Indeed, the long opening movement of the 35-minute Cello Concerto Op 61 had something of the elegiac, nobly sequential feel of a Swiss Elgar – except that he composed it in the wake of the Second World War, not the First. An uneven work, perhaps, which seemed to change direction stylistically as it proceeded towards its crazily upbeat ending – but projected with an unflagging security, eloquence and warmth by the young Swiss cellist Christian Poltera in a solo part that barely lets up for a bar.

Yet the real find of the concert was a one-movement nocturne for strings, based on a poem about harvesting in moonlight by Schoeck's compatriot, Gottfried Keller, composed in 1945 and entitled Sommernacht. This crepuscular web of unfolding lines, later yielding to a kind of tranced, lilting dance touched by high sonorities and nightingale figuration for solo violin, provided 14 minutes of mystery and enchantment, beautifully played and warmly received.