You have been warned, however, that the entire Diamond & Pearl music collection would span up to 149 tracks, and you can also opt to purchase them on an individual basis for $0.99 if you so desire. It makes perfect (financial) sense then to pick up the entire shebang for less than $10, just in case you were about to make a dash for the calculator (or fire up the calculator app on your smartphone).
To date, Nintendo has actually gone through the whole Pokemon collection and rolled out the soundtracks of every installment up until Diamond & Pearl, where they began right at the start with Fire Red and Leaf Green. Up next would most probably be Pokémon Black & Pokémon White, where it will be followed by Pokémon Black 2 & Pokémon White 2.