Billie Holiday was an American jazz singer and songwriter. Nicknamed Lady Day by her sometime collaborator Lester Young, Holiday was a seminal influence on jazz, and pop singers' critic John Bush wrote that she "changed the art of American pop vocals forever." Her vocal style—strongly inspired by instrumentalists—pioneered a new way of manipulating wording and tempo, and also popularized a more personal and intimate approach to singing. She co-wrote only a few songs, but several of them have become jazz standards, notably "God Bless the Child," "Don't Explain," and "Lady Sings the Blues."