Folk music is a genre of music, very popular in the 50s and early 60s. This was known as the Folk Revival. Traditional folk are older songs, known by many people, but the artist unknown, typically with strong lead lyricist, accoustic guitars, and harmonicas. These evolved into regular Folk, which used the same instruments, but had more modern concepts and artists known. Folk songs typically have strong, profound lyrics about the artist's view of the world, expressing strong emotion, or tell a story. Folk later changed with the time and became Folk Rock, and Electric Folk. Country is technically a sub category of Folk. Many famous folk artists are Bob Dylan, Neil Young, Joan Baez, Paul Simon, and Johny Cash.
The Time's They are a-Changing and Ring of Fire are famous Folk music.