As you’re putting your child to bed rock him/her gently and sing softly to him/her. Pay attention to how he/she tells you he/she wants more singing. Does he/she turn his/her head toward you? Smile? Move? What does he/she do to say “enough”? Cry? Turn away? Take note of how to respond to his/her cues now and in the future!
Singing to your child before bedtime is like a calming conversation using music. You sing, he/she responds, you respond etc. He/She is learning how it feels to calm himself/herself, which is an important life lesson.