To provide a controller and a music reproducing device in which display contents that are related to a music and being displayed while the music is reproduced are speedingly and simply switched to a time display.

An operating section (a mode button 32a) which is provided to manually input operations related to the reproducing of a music and a display section 33 which displays the operational information of the operating section and information related to music are provided. When detection is made for an operation which is maintained for more than a prescribed time in the operating section while a reproducing of a music is conducted, all of or a portion of the information being displayed on the section 33 is switched to time data and simultaneously the reproducing of the music is continued.