It sounds like you're asking about "Miku who can't sing." If you're referring to Hatsune Miku, she is a virtual singer—a Vocaloid software voicebank developed by Crypton Future Media. Hatsune Miku herself doesn't "sing" in the traditional human sense; instead, her voice is synthesized using samples from a voice actress. The quality of her singing depends on how users program the notes and lyrics in the Vocaloid software. If you mean a version or parody of Miku who "can't sing," there are many fan-made videos and memes where Miku is humorously portrayed as singing badly or off-key, but officially, Hatsune Miku is designed to produce clear, melodic singing. Would you like me to share more about how Vocaloid technology works or examples of Miku's music?