Johnny “Big Moose” Walker (June 27, 1927 – November 27, 1999) was an American Chicago blues and electric blues pianist and organist. He worked with many blues musicians, including Ike Turner, Sonny Boy Williamson II, Lowell Fulson, Choker Campbell, Elmore James, Earl Hooker, Muddy Waters, Otis Spann, Sunnyland Slim, Jimmy Dawkins and Son Seals.^[2]

Walker was primarily a piano player but was also proficient on the electronic organ and the bass guitar (he played the bass guitar when backing Muddy Waters). He recorded solo albums and accompanied other musicians in concert and on recordings.

John Mayon Walker was born in the unincorporated community of Stoneville, Mississippi, partly of Native American ancestry. He acquired his best-known stage name in his childhood in Greenville, Mississippi, derived from his long, flowing hair. He learned to play several instruments, including the church organ, guitar, vibraphone and tuba.

He began his musical career as a pianist, in 1947, touring with various blues bands and backing such notable artists as Ike Turner, Sonny Boy Williamson II, Elmore James, Lowell Fulson and Choker Campbell. Walker served in the United States Army from 1952 to 1955, serving during the Korean War. In 1955, billed as Moose John, Ultra Records released the single, “Talkin’ ‘Bout Me”. His own recordings, released under various names, were unsuccessful, but Walker started working more consistently in the mid-1950s, notably backing Earl Hooker and Elmore James.Walker moved to Chicago in the late 1950s and over the next decade accompanied Sunnyland Slim, Otis Rush, Muddy Waters (for whom Walker played bass guitar), Ricky Allen, Little Johnny Jones, and Howlin’ Wolf.^[4] In 1960, he accompanied Junior Wells on his best-known recording, “Messin’ with the Kid“. The following year Walker played on James’s recordings of “Look on Yonder Wall” and “Shake Your Moneymaker“. In 1962, Walker played on Waters’s recording of “You Shook Me“. During the 1960s, a couple of obscure Chicago-based record labels, Age and The Blues, released Walker’s solo singles.