The Keef Hartley Band is a British rock and jazz rock band formed in 1968 by drummer Keef Hartley. Their core included Miller Anderson on guitar and vocals, and Gary Thain on bass. Notable session musicians such as Mick Weaver on keyboards and Chris Mercer on saxophone contributed to their sound. They released their debut album Halfbreed (1969). That same year, they performed at the Woodstock Festival on the second day. Their style evolved from John Mayall's blues, incorporating solid songwriting and jazzy arrangements with prominent brass sections. Their lineup changed over time, notably when Hartley parted ways with Anderson in 1971 to form a more funk-oriented group featuring Junior Kerr. They released the albums Battle of NW6 (1969), The Time Is Near (1970), Overdog (1971), and the live album Little Big Band (1971). This new formation released Seventy Second Brave (1972) before disbanding in 1972. The posthumous album Not Foolish Not Wise (1999) features live recordings from their later lineup.