Spannungen ("Tensions" or "Voltages") is an annual summer festival for chamber music in Heimbach, North Rhine-Westphalia, Germany, founded by pianist Lars Vogt in 1998.

Lars Vogt, who appeared internationally as a soloist with renowned orchestras, was a dedicated chamber musician, focused on the repertoire of music from the classical period and the romantic era.

He founded the festival Spannungen for chamber music in Heimbach in 1998, to perform annually with friends and colleagues in a historic power plant built in 1905.

[4] The location, Kraftwerk Heimbach, is a hydro-electric power station in Jugendstil, with old turbines, brass features and Art Deco lamps.

[4] Artists of the first festival in 1998 included, besides Vogt, hornist Marie Luise Neunecker, clarinetist Michael Collins, violinists Christian Tetzlaff and Antje Weithaas, violists Tatjana Masurenko and Tabea Zimmermann, cellists Truls Mørk and Boris Pergamenschikow, and pianist Alexei Lubimov.