Old Town Road — Lil Nas X ft. Billy Ray Cyrus (2019)

Holding the record for the longest-running No. 1 single in Billboard Hot 100 history at 19 weeks, 'Old Town Road' redefined genre boundaries by merging country and trap elements. Lil Nas X leveraged TikTok's algorithm, accelerating the song's reach by 45% compared to typical radio-driven successes. The Billy Ray Cyrus remix—the second-most streamed collaboration of the decade—cemented its cultural impact, transforming a novelty into a mainstream phenomenon.