Blue Effect was a Czech rock band formed in 1968 and also known as M. Efekt, Modrý efekt, and the Special Blue Effect. Led by guitarist Radim Hladík, who was the only constant member until his passing in 2016, the group was known for its dynamic evolution in sound, moving from blues rock to jazz fusion and art rock. Recognized for their innovative approach and musical versatility, Blue Effect played a significant role in shaping the Czech rock scene.