In 2003, at the age of sixteen, Lamar released his first full-length project, a mixtape titled Youngest Head Nigga in Charge (Hub City Threat: Minor of the Year), under the pseudonym K-Dot. The mixtape garnered enough local attention for Lamar to secure a recording contract with Carson-based indie record label Top Dawg Entertainment (TDE).He then released a twenty-six track mixtape two years later titled Training Day (2005). Throughout 2006 and 2007, Lamar, alongside other up-and-coming West Coast rappers such as his TDE label-mate Jay Rock and Ya Boy, toured and opened for veteran West Coast rapper Game. Lamar, under his moniker K-Dot, was also featured on Game’s songs “The Cypha” and “Cali Niggaz”.In 2008, Lamar made a brief cameo appearance in the music video for his Top Dawg label-mate Jay Rock’s commercial debut single, “All My Life (In the Ghetto)”. More recognition came Lamar’s way after a video of a Charles Hamilton show surfaced, where Hamilton went in the crowd to battle fellow rappers in attendance. Lamar did not hesitate and began rapping a verse over Miilkbone’s “Keep It Real”, that would later appear on a track titled “West Coast Wu-Tang”. After receiving a cosign from American hip hop superstar Lil Wayne, Lamar released his third mixtape in 2009 titled C4, heavily themed around Wayne’s Tha Carter III LP. Soon after, Lamar decided to drop K-Dot as his stage name and go by his birth name. He subsequently released a self-titled extended play (EP) in late 2009. In 2009, Lamar also formed Black Hippy, a supergroup with label-mates and fellow California-based rappers Jay Rock, Ab-Soul and Schoolboy Q.