I am new here.
Please tell me, OK??

You need to get 2 books:

One is the Book of Magical Dances No.1
and the other is the Book of Magical Dances No.2

The second you get from defeating everyone in the cave on the Mushroom Rock Road in chapter 5. I cannot remember where you get the first one from

it help if u have the stratagy giud

To obtain the other book, defeat The Experiment at Djose Temple when all of its levels are at 5.

to get magical dance vol.1 fight in den of woe and win . then to get magical dance vol.2 you have to make sure that the experiment in djose temple has reach level 5 on all stats. then enjoy this new ability for songstrees

Taken directly out of the FF X-2 guide book: "To learn "MP Mambo" and Magical Masque", you must aquire to key items: Magical Dances, Vol. I and Magical Dances, Vol. II. Volume I is obtained by defeating the boss enimes inside the Den of Woe at Mushroom Rock. Volume II is obtained by defeating the Experiment machine at Dojse Temple during chapter 5, when the boss's Attack, Defense, and Special parameters are all at level 5" That was just to clarify it if anybody was confused by the explanations on top.

i already said that dualface. dont you dare copying me. toy son of a sea.

Haha, you are banned.

Ultimate's said it all.