Answer:
1.637 x 10¹⁴ different playlists
Explanation:
Since DJ Ali needs to choose 9 songs and wishes that the number of blues, country and jazz songs are the same, she needs to pick 3 songs of each type. The total number of ways she can choose the songs, without considering their order is:

The number of possible ways of ordering those nine song is:

There are 1.637 x 10¹⁴ different possible playlist.