sentences:  Playing in many jazz formations, he quickly got into the swing of jazz music and became a regular performer in major jazz festivals in Varna, Apollonia, Plovdiv, Rousse and others.Yankoulov spent the longest time of his career in the band Zone C, founded in 1994 with Vesselin Vesselinov-Echo (bass) and Vasil Parmakov (piano).Misho Grozdanov, Vladko Karparov (saxophone), and Ateshghan Yuseinov (guitar, tambura) joined the band later.