The pianist Bud Powell , who died in 1966, aged 41, altered the course of jazz piano through his bebop innovations in the 1940s and left behind an impressive legacy of recorded material that also charts his slow decline as a result of mental illness and addiction problems. Alyn Shipton suggests the best examples of his work and is joined by pianist Geoff Eales to consider Powell's output for the Blue Note label. Producer Simon Poole