If you're keeping track, Super Music Collections for Pokemon FireRed/LeafGreen, Pokemon X/Y and Pokemon HeartGold/SoulSilver were released over the past several months. This leaves soundtracks for Pokemon Diamond/Pearl, Pokemon Black/White and Pokemon Black2/White2 off iTunes, all of which are noted as upcoming releases in the Ruby/Sapphire press release.
Of course, with Nintendo planning to add GBA games to the Wii U Virtual Console in April and DS games in the works, you could always wait to see if every main Pokemon entry shows up there instead. Other than the 3DS' Pokemon X/Y, of course.
Released in North America in March 2003, Pokémon Ruby and Pokémon Sapphire were set in the island region of Hoenn, based on a real-world location, with the composers-Junichi Masuda, Gō Ichinose, and Morikazu Aoki-taking much of their inspiration from the Japanese island of Kyushu. Over ten years after the games' original launch, the soundtrack releasing today includes beautifully adapted and orchestrated versions of their music.
Fans looking to complete their collections can look forward to more from the Pokémon musical archives with upcoming Super Music Collections from:
Pokémon Diamond and Pokémon Pearl
Pokémon Black and Pokémon White
Pokémon Black 2 and Pokémon White 2
Today's launch follows other digitally remastered soundtracks in the Super Music Collection series. These have included Pokémon X & Pokémon Y, Pokémon FireRed & Pokémon LeafGreen, and most recently, Pokémon HeartGold & Pokémon SoulSilver.
Pokémon Ruby & Pokémon Sapphire: Super Music Collection can now be downloaded on iTunes here: https://itunes.apple.com/us/album/pokemon-ruby-pokemon-sapphire/id820996217