Square Enix are releasing a series of four compilation LPs with character and battle themes from all 15 Final Fantasy main series titles.
Each release will be a single black vinyl LP. They will be housed in tip-on single-pocket jackets with character illustrations by Tetsuya Nomura and will all include a download card. There is also an option for a version which has all four releases together in a clear plastic slipcase
Please note that if you order from Square Enix Japan you will have to buy all four standalone titles in order to qualify for the slipcase, while the Western stores has the 4LP set as a standalone listing.
It is also available to preorder outside of Japan from CDJapan here and Amazon Japan here, however I don’t think there’s any rush to import this from Japan as it will likely become available on both the EU and NA Square Enix stores later on.