This 1991 music video released by Motown Records features celebrities ranging from Smokey Robinson to David Bowie to Diana Ross.
The song has also been covered by bands as diverse as The Strokes (below) and Boyz II Men (bottom).

Mercy Mercy Me (The Ecology)

Marvin Gaye
1968

In Mercy Mercy Me the Prince of Motown, Marvin Gaye croons that “things ain’t what they used to be” before running through some of the environmental ills that faced the people of 1960’s America, including the state of the oceans and fears of radiation.  The song became one of Gaye’s most iconic hits and helped the album it first appeared on, What’s Going On, sell more than a million copies, the first of his works to do so.