My tip is buying a +10 exp boost, instantly boosts your xp gained from every mission. music lessons will go from 120xp to 240 xp. cons are that it is very expensive at the moment, cheapest one is at 70+ hive.
then from there, if energy isn't a problem, just grind xp in shopping mall but if you cany have enough energy consistenly, then music lessons. :) hope this helps.

also count me in for the giveaway hehe
@maggotmilk

!PIZZA