James Taylor pays tribute to slain MIT officer Sean Collier

Singer-songwriter James Taylor performed one of his classic ballads in Cambridge, Mass., on Wednesday at a memorial service held for Sean Collier.

Collier, a 26-year-old Massachusetts Institute of Technology police officer, was shot in the head execution-style in his patrol car on April 18, three days after the Boston bombings. Law enforcement officials believe Collier was murdered by bombing suspects Tamerlan and Dzhokhar Tsarnaev.

In addition to Taylor, Vice President Joe Biden also attended Collier's memorial along with thousands of other mourners.

Taylor sang a heartfelt rendition of "Shower the People," the opening track from his 1976 album, "In The Pocket."

A sampling of the song's lyrics: "Shower the people you love with love/Show them the way you feel/Things are gonna be much better if you only will."

Watch video above to see Taylor perform at the service.