The IEEE Signal Processing Society announced the fourth edition of the Signal Processing Cup: a real-time beat tracking challenge. The beat is a salient periodicity in a music signal. It provides a fundamental unit of time and foundation for the temporal structure of the music. As Meinard Müller says (Fundamentals of Music Processing, Springer, 2015), “It is the beat that drives music forward and provides the temporal framework of a piece of music. Intuitively, the beat corresponds to the pulse a human taps along when listening to music.”