He invented karaoke, saw it take off, then walked away – Daisuke Inoue taught the world to sing, if not always in harmony

• Daisuke Inoue didn’t consider he had invented anything when he launched the karaoke machine. Last year alone he missed out on US$100 million in royalties
• But he’s not bitter, and happily tells the story of his creation – which turns 50 next year – and how it changed his life and that of millions of singers