Final answer:
Annie was likely listening to an upbeat and danceable mix of genres on her playlist called Annie Dances, possibly including 90s songs and big band music.
Step-by-step explanation:
We can make an educated guess about the type of music Annie was listening to on her playlist called Annie Dances based on the information given regarding Bibi. Bibi's enjoyment of singing mash-ups of 90s songs and big band music suggests a fun, upbeat, and danceable mix of genres. Therefore, it is likely that Annie's playlist, Annie Dances, would include a similar variety of lively music that is suitable for dancing, reminiscent of the mix that Bibi enjoys.