A long-lost concerto, once attributed to Sperger, is now confirmed as Pleyel’s and will premiere in 2026.

A lost classical concerto, "Concerto per Violone," originally thought to be by Johannes Sperger, has been rediscovered and attributed to Ignaz Joseph Pleyel, a prominent contemporary composer. The piece, written for a five-stringed Viennese double bass and a typical early 19th-century orchestra, will premiere in October 2026 with the Australian Brandenburg Orchestra. Musicologist Darija Andzakovic identified Pleyel as the true composer by matching handwriting to his known manuscripts. The concerto, possibly performed in Pressburg (now Bratislava), has not been heard since its original composition and features editorial markings suggesting collaboration between the two composers.