For example, provided is an information processing device with which the entire performance can be felt really visually.The information processing device TB according to the present invention includes a processor performing a reception process of receiving input of performance information including pitch information, a first image output process of outputting a first image according to the received performance information, a performance determination process of determining at least any of tonality, a chord type, and a pitch name on the basis of the received performance information, and second image output process of outputting a second image according to a result determined in the performance determination process.