http://en.wikipedia.org/wiki/27_(number)
"Many talented and famous rock/blues musicians died at age 27. These include Robert Johnson, Janis Joplin, Jimi Hendrix, Brian Jones, Jim Morrison, Ron "Pigpen" McKernan, Pete Ham, Richey Edwards, Kurt Cobain and Amy Winehouse. The musicians who died at this age are often referred to as the 27 Club."