"Ohio" is a protest song written and composed by Neil Young in reaction to the Kent State shootings of May 4, 1970, and performed by Crosby, Stills, Nash & Young. It was released as a single and peaked at #14 on the Billboard Hot 100.
First formed in the early '50s, the Isley Brothers enjoyed one of the longest, most influential, and most diverse careers in the pantheon of popular music -- over the course of nearly a half century of performing, the group's distinguished history spanned not only two generations of Isley siblings but also massive cultural shifts which heralded their music's transformation from gritty R&B to Motown soul to blistering funk.
"Machine Gun" is a song written by American musician Jimi Hendrix, and originally recorded by Band of Gypsys for their self-titled live album (1970). It is a lengthy, loosely defined (jam-based) protest of the Vietnam War, and perhaps a broader comment on conflict of any kind.