The great thing about the Song List on DX is that now everyone has access to every monster in the game, rather than being limited by a personal collection of CDs. (You still have to make your own unlock progress in-game of course).
The entire Song List for MR1&2DX has been solved too! LegendCup has an app to pick a Main breed and Sub breed and see every unique variant of every possible pure and mixed breed now as well. (Or you can use the "Random" button if you live for the thrill)