How to get through the four levels of the 626 horror hotel?

You chose to turn on the microphone at the beginning, so the music stopped. As soon as the microphone logo appears, the English prompt next to it lets you sing that lullaby, which is the music that stopped before.

If you don't choose to turn on the microphone before the game starts, but only choose the camera, or neither of them is turned on, then after the music stops, there is no microphone sign, but a circle with a ball. At this time, you can move the mouse on the screen to let the music continue, and the dots in the circle will rotate with your mouse. If you are lucky, the concert will be played smoothly until you pass, otherwise the kid will be awakened by intermittent playing.