Booker T. & the M.G.'s are a rhythm and blues (R&B) band that are important in the history of soul music. They started in 1960 when they played instrumental music for singers. They did not sing themselves. They worked at Stax Records, and played music on hundreds of important records by famous singers such as Wilson Pickett, Otis Redding, Bill Withers, Sam & Dave, Carla Thomas and Rufus Thomas and Johnnie Taylor.
They also make their own records. As they do not sing, these are instrumental records - music without singing. In 1962 they made a record called "Green Onions" which was a single, and this was a success. People liked the sound of their music, and by the mid-1960s, bands in America and in Great Britain were trying to copy their sound.
People liked them so much and felt they were so important they were given an award of being named in the Rock and Roll Hall of Fame in 1992.