Musician William "Billy" Cox is one of two bassists to have played regularly with legendary guitarist Jimi Hendrix. Cox was born October 18, 1941, in Wheeling. Growing up, Cox's parents encouraged him to play music, and his early interests included piano and saxophone. His family lived near the Capitol Music Hall, and Cox listened to the shows through an open side door.

Cox's family moved to Pittsburgh where, in his senior year of high school, he was taken with the sound of the electric bass. After graduating, Cox joined the Army and was stationed at Fort Campbell, Kentucky. One evening in 1961, Cox heard Private James Hendrix playing at the base's service club. The two quickly forged a strong musical bond. After Hendrix was discharged, they moved to Nashville and formed the King Kasuals. Cox, who was struggling to make ends meet, declined offers to join Hendrix, who first backed Little Richard and then traveled to England where he put together his band, the Experience. Instead, Cox played in the house band of Noble Blackwell's Night Train, a local rhythm and blues television show. In spring 1969, Hendrix asked Cox to replace bassist Noel Redding in a new band, just in time to play at the music festival at Woodstock, New York. He also played the band's 1969 New Year's Eve and New Year’s Day performances at the Fillmore East that was released as Band of Gypsys.

Sensing that things were spiraling out of control, Cox left the tour and returned to Nashville, not long before Hendrix died of an accidental overdose. Cox went on to play with Charlie Daniels and was sought after for work in studio sessions. More recently, Cox appeared with Buddy Miles on The Band of Gypsys Return in 2006, and he continues to work with the organization run by the Hendrix family called Experience Hendrix. In the 21st century, Cox has released three solo albums: Last Gypsy Standing (2009), Old School Blue Blues (2011), and Unfiltered (2014), in addition to appearances on various compilations and live recordings featuring Hendrix.

Cox was inducted into the West Virginia Music Hall of Fame in 2011.