Others sing for money, and I sing for my life.

I just like singing, not a professional singer.

"Others sing for money, I sing for death" is a self-deprecating statement, which shows that my singing level is not high, which will make the audience feel uncomfortable or unbearable. The response of "I just like singing, not a professional singer" is to express my love for singing in a humorous way, rather than demanding myself by professional standards. This kind of response can not only resolve the embarrassment, but also show your confidence and optimism.