Lossless audio is exclusive to Apple Music and requires a subscription; it’s not available for purchase, nor can you upgrade purchased music or get it through iTunes Match.
Millions of tracks now offer immersive, Dolby Atmos-powered mixes that Apple claims deliver “true multidimensional sound and clarity.†There will be a much smaller selection of spatial audio tracks than lossless ones, however, with Apple promising “thousands†of spatial audio tracks on day one with more to follow.