Final answer:
The coon song ushered in the popularity of ragtime by introducing syncopation.
Step-by-step explanation:
The coon song played a significant role in popularizing ragtime by introducing syncopation. Syncopation is a rhythmic technique where the emphasis falls on the offbeat or weak beats instead of the strong beats. This created a lively, energetic, and distinctive sound that set ragtime apart from other genres. The coon song's syncopation style influenced composers and musicians to incorporate it into their own compositions, leading to the rise in popularity of ragtime.