Kelly Bailey

Kelly Bailey was the senior game designer of sound and music at Valve, conceptual artist and the main composer of the Half-Life series music. On Valve's official website, his function was described that way: "Kelly is Valve's senior audio producer, responsible for creating sound effects & music."

Bailey also built the test chamber disaster sequence featured at the beginning of Half-Life with John Guthrie in a weekend, during which they worked for 48 hours straight. After going home at the end of the weekend and coming back in the offices on Monday, "still in a zombielike state", Guthrie and Bailey were glad to see that the rest of the team loved the sequence after playing through it. He also sketched out the journey through Silo D for the Half-Life chapter Blast Pit.

It appears Bailey used samples from other existing soundtracks in his works, or at least used stock sounds also used by other artists. For instance, the track "Radio" from the Half-Life 2 soundtrack can be heard during the 2002 film 28 Days Later, in the background at 00:26. Another example is the track "A Red Letter Day" from the Half-Life 2 soundtrack, that makes up the start of the track "London Deserted", this time from the soundtrack of the 2007 film 28 Weeks Later, the sequel to 28 Days Later. Whether this was made by complete chance or not is unknown.

Half-Life 2's Gordon Freeman's face was based on him, among other Valve employees, such as David Speyrer, Eric Kirchmer and Greg Coomer.

In March 2011, it came to light that Kelly Bailey had left Valve for reasons unknown, the news causing some concern and displeasure from the Steam community due to the lack of any public farewell or notification regarding Bailey's depature.

Work for the Half-Life series

 * Half-Life (including its soundtrack) (1998)
 * Half-Life 2 soundtrack (2004)
 * Half-Life 2: Episode One soundtrack (2006)
 * Portal soundtrack (with Jonathan Coulton for Still Alive) (2007)
 * Half-Life 2: Episode Two soundtrack (2007)

Trivia
His name appears in Half-Life as an Easter egg on a Sector C locker and can be heard in announcements.