To support the playing of a foot-operated element group (a pedal keyboard) that comprises a plurality of foot-operated elements (pedal keys) that are operated by the feet of a player, the present invention displays, on a display screen (200), a foot-operated element image (a pedal keyboard image PIM) that shows the foot-operated element group. The present invention also: acquires chord informationthat indicates chords to be played; and specifies the pitches of base notes that correspond to the chords indicated by the acquired chord information. The present invention also visually designates (marker MK3) specific foot-operated elements in the foot-operated element image (PIM) displayed on the display screen (200) that correspond to the specified base note pitches. The present invention also displays, on the same display screen, display items that indicate chord names. The present invention could, for example, display display items that indicate one or more chord names that correspond to a chord progression over a plurality of measures and, as playing progresses, add a display (marker MK1) that emphasizes the display item that indicates a specific chord name.