Automatic conversion of Pop music into chiptunes for 8-bit pixel art

In this paper, we propose an audio mosaicing method that converts Pop songs into a specific music style called “chiptune,” or “8-bit music.” The goal is to reproduce Pop songs by using the sound of the chips on the old game consoles in 1980s/1990s. The proposed method goes through a procedure that first analyzes the pitches of an incoming Pop song in the frequency domain, and then synthesizes the song with template waveforms in the time domain to make it sound like 8-bit music. Because a Pop song is usually composed of the vocal melody and the instrumental accompaniment, in the analysis stage we use a singing voice separation algorithm to separate the vocals from the instruments, and then apply different pitch detection algorithms to transcribe the two separated sources. We validate through a subjective listening test that the proposed method creates much better 8-bit music than existing nonnegative matrix factorization based methods can do. Moreover, we find that synthesis in the time domain is important for this task.