The process of transplanting music between cultures is not without criticism. The folk revival of the mid-20th century, for example, appropriated the music of various rural peoples, in part to promote certain political causes, which has caused some to question whether the process caused the "commercial commodification of other peoples' songs... and the inevitable dilution of mean" in the appropriated musics. The issue of cultural appropriation has also been a major part of racial relations in the United States. The use of African American musical techniques, images and conceits in popular music largely by and for white Americans has been widespread since at least the mid-19th century songs of Stephen Foster and the rise of minstrel shows. The American music industry has actively attempted to popularize white performers of African American music because they are more palatable to mainstream and middle-class Americans. This process has been related to the rise of stars as varied as Benny Goodman, Eminem and Elvis Presley, as well as popular styles like blue-eyed soul and rockabilly.