a miku who can't sing

It sounds like you're referring to "Miku who can't sing." If you're talking about Hatsune Miku, the famous virtual singer and Vocaloid software voicebank, she is actually designed to sing digitally using synthesized vocals. However, some people joke or create content imagining what it would be like if Miku couldn't sing well, often for comedic or creative effect. If you mean a specific version, parody, or character inspired by Miku who "can't sing," please provide more details! I can help explain or find related content. Would you like to know more about Hatsune Miku's singing capabilities, Vocaloid technology, or something else related?