The development dataset contains 6000 MIDI files with monophonic melodies generated by artificial intelligence algorithms. The tempo is between the 68bpm and 118bpm (beat per minute). The length of each melody is 8 bars, and the melody does not necessarily include complete phrase structures. There are two datasets with different music styles used as the training dataset of a certain number of algorithms, where the melodies in the development dataset are generated. The website of the challenge: http://www.csmcw-csmt.cn/data/2020/ai-composition-recognition2020 (Chinese instruction) https://ai-composition-recognition2020.github.io/english.html (English instruction)