Folk music covers such a broad expanse of musical history that any single definition is nearly impossible to pin down. With one meaning, it is represents the music of the people handed down via oral tradition, without the means of mass communication as in the modern form. It was the complement of tales and folk dances in the pre-industrial past. The narrative structure of folk music gives it a wide range of subjects to cover. Early in its recorded history, this included local mythologies, Biblical verse, nonsense rhymes, and lyrics commemorating victory, defeat, or lives lost in battle. Of course, degrees of variation exist between the folk music of one culture and another, but it is generally agreed that Folk music has been a significant reflection of the way of life and lore in distinct communities worldwide. While the beginnings of American folk rose out of slave spirituals, the subject matter of folk can be generalized to any suffering and labor-related themes that were the bane of a particular community. Folk music passed down in the traditional sense of oral inheritance has been replaced by a means of mass transmission that has propelled other genres to commercial success in the past century or so. However, this did not mean the music and themes of traditional folk had vanished. In the 1930s, a revival of folk music was owed in large part to the Great Depression and the ensuing hardships of a generation lost to capitalism's volatility. Woody Guthrie harnessed his experiences wandering the Dust Bowl with his fellow unemployed into folk songs dealing with the labor problems of the time. Guthrie was the inspiration for a slew of folk revivalists in the 1960s: Bob Dylan, Joni Mitchell, Phil Ochs, and Joan Baez. 1970s Folk was molded much by artists like Cat Stevens and James Tayler, who often dealt with relationships in their lyrics. Folk remains alive and well in the present, as songwriters such as Dar Williams and take to the stage and huge folk festivals.