The (re)creation and distribution of cultural products such as music are increasingly shaped by digital platforms. This study explores how TikTok and Spotify, situated in different governance and user contexts, could influence digital music production and reception within each platform and between each other. Focusing on daily hit song charts as the embodiment of platformization, we collected and analyzed a two-year longitudinal dataset on TikTok and Spotify. We tested the relationships between elements of platformization and hit song popularity within each platform, and examined cross-platform influence flow. Results reveal significant differences in major label, genre, and content features among hit songs on TikTok and Spotify, which can be explained by their distinct platformization practices. We also found some evidence that hit song popularity on Spotify might precede that on TikTok. This study illustrates both the platform-specific mechanisms of TikTok and Spotify and their interconnectedness in the cultural production ecosystem.