Because you have to do frame by frame movements and depending on how smooth you want your animation to be would depend on how many frames are required.
Vibrato. It’s the same in vocals, changing pitch quickly in a way that sort of sounds like a vibration, though the technique itself is not called vibration.
Answer:
The Music Director coordinates and schedules all performances for their musical group. In cooperation with the organization for which they work, they develop calendar and coordinate with the appropriate contacts to plan and schedule performances. In the case of a Music Director for a radio station or television show, they coordinate music interviews and set up live performances for the show.