SIGNAL are a Bulgarian rock band formed in Sofia in June 1978 by Yordan Karadzhov, Hristo Lambrev, Rumen Spasov, and Georgi Kokalanov. They recorded their first album Vechen Krastopat/Eternal Crossroads in 1979. In their 30-year long career they have released 11 studio albums and have had thousands of gigs. They were special guests at Battle of the Bands in 2014.