Greydon Square (born Eddie Collins on September 28, 1981) is an American rapper. He is an Iraq War veteran and an outspoken atheist who promotes discussion on philosophical issues, as well as having studied physics full time before moving on to study computer science.
Collins grew up in Compton, California, an impoverished suburb of Los Angeles, where he was raised as an orphan and became immersed in gang culture. In May 2001, he enlisted in the United States Army and served in the Iraq War in 2004. After his discharge, Collins began attending college in Phoenix, Arizona as a physics major. At this time he began questioning his religious beliefs and eventually became an atheist, posting videos on YouTube. He has appeared in several television documentaries and radio shows, and his music has attracted fans such as Penn Jillette and Richard Dawkins. He is also a member of the international secular hip-hop activist movement The Anti-Injustice Movement (aka AIM Clika) and runs his own organization Grand Unified Theory, which uses creativity to educate people about science and rational thinking.
Music career 
Collins has been expressing himself through rap under his stage name of Greydon Square since 2004. Among his influences are Phil Collins, DJ Quik, Dr. Dre, Quincy Jones, Stanley Clarke, Cedric Williams, and The Bee Gees. His first album, Absolute, was released in 2004 and is no longer available. His follow-up album The Compton Effect, was released in 2007 after much delay. After being approached by several independent record labels and one major one, Collins created his own company to distribute the record. In 2008, he released his second album The CPT Theorem. The titles of these two albums are references to the city of Compton (also called CPT) where he grew up, and to the Compton effect and the CPT Theorem from physics, which he studies. His music deals with philosophical issues (particularly with regard to atheism and science), political issues, the war in Iraq and his experiences as a soldier who had to fight in this war, and his childhood which he had to spend in group homes.
In 2010 he announced the release of his third studio album, The Kardashev Scale, along with an EP titled Serpents of Eden in collaboration with Adil Omar. He's also a confirmed guest on Omar's debut solo album The Mushroom Cloud Effect alongside Kool G Rap on a song titled "Summertime".
The song titled "War Porn" from his latest album The Kardashev Scale was performed in collaboration with hip-hop artist Canibus.