Answer:
I think that there needs to be a bit more context for this question
(what are yo currently studying). There are several interoperations that are possible. Do the songs matter, or is it just sad vs happy?
if titles don't matter than I guess the answer would be 12: 1 sad, then 2 sad, then 3 sad, et. up to 12. The happy ones don't matter because there less sad ones. I think you are wanting to consider "combinations". Once again
the upbeat list should not matter... if you add only one sad song you can have 12 lists. If you add two sad songs the combinations are 66 (see the list)
If you consider all sad song unique quantities, then 4095 would be the total
C(n,r)=(nr)=n!/(r!(n−r)!)
1-12
2-66
3-220
4-495
5-792
6-924
7-792
8-495
9-220
10-66
11-12
12-1
total--4095
Step-by-step explanation:
