In the mid-1960s, singer-songwriter Gordon Lightfoot began moving his folk songs into a folk-rock direction with recordings such as the percussion-driven "Black Day in July" about the 1967 Detroit riot. He would rise to top the charts in the 1970s with a number of his folk-rock recordings such as "Sundown" and "Carefree Highway" and eventually become known as a folk-rock legend. Some artists who originally produced with a harder edged rock sound found the ability to communicate more easily and felt more genuine in this method of delivery. In this category was Cat Stevens, who began in London much like the Byrds did in the United States but toned down the sound more frequently with acoustic instruments. He performed songs that contained concern for the environment, war, and the future of the world in general. The Canadian singer-songwriter Joni Mitchell won many Grammy Awards with her folk rock/pop songs.