This is in the context of a person who plays recorded music at a party or club. Referring to such a person as a "disk jockey" or "jock" seems hopelessly old fashioned. Three variants are in vogue and all are heavily used. Wikipedia redirects deejay to disc jockey and states it is "also known as DJ." From the NYT in 2011: "a not-so-green affair with 50 to 80 people at a hot club with an open bar and a hip-hop deejay." The same source a couple of days ago: "after having spent 30 years as an entertainment industry functionary — as a D.J., promoter and record label exec."
The Washington Post earlier this month wrote: "Martin Solveig will serve as the house deejay at the Gibson Amphitheatre show." Also, many stage names in the music business favor one form, as in DJ Spooky, DJ Jazzy Jeff, DJ Skribble, etc.
Is there a preferred version of the term?