The ESP AM J-4 is an electric bass used by Prince on the One Night Alone tour. It is a Jazz-style bass with an orange finish. It was one of several guitars purchased in Tokyo in 2002 (alongside the Daisy Rock Heartbreaker Artist, ESP XJ-Crystal and Fender Japan ST57-70TX Stratocaster). Prince went on to play this bass on the tour.
It is now on display in Paisley Park.