Procol Harum is a British rock band formed in 1967, best known for their hit song "A Whiter Shade of Pale." The band is often credited with pioneering the progressive rock genre, blending rock with classical music elements. Their sound features rich orchestration and poetic lyrics, which set them apart from many of their contemporaries. The original lineup included lead singer Gary Brooker, lyricist Keith Reid, and several talented musicians. Over the years, Procol Harum has undergone various lineup changes but has maintained a loyal fan base. Their music continues to influence artists and is celebrated for its artistic depth and innovation.