Tau

Piotr Kowalczyk, better known under his stage name Tau, and formerly as Medium, is a Polish rapper, singer and record producer. In 2008, he released his underground debut album Seans spirytystyczny (Séance) under the name Medium. His next underground album Alternatywne źródło energii was released in 2010, which helped Medium to be spotted by Marcin "Tytus" Grabski, CEO of Asfalt Records, who offered him a contract.