Here's a test to measure your tone-deafness. It plays two sequences of music and asks you whether the two are identical. There's 36 sequences and it is purposefully very difficult. Over 85% means you have potential as a world class musician - although I wonder why you'd have to score less than 50% to be 'tone-deaf' - a tone-deaf monkey randomly pressing the buttons will score better than 50%, 50% of the time. Maybe using a 'don't know' button here would help to improve the accuracy.