Answer
$\approx0.868$
Work Step by Step
Following the example: $P(\text{not hearing song})=\frac{_{11}C_4}{_{12}C_4}$
Hearing the songs on each day is independent, hence the probability we are looking for is: $P(\text{hearing song})=1-(\frac{_{11}C_4}{_{12}C_4})^5\approx0.868$