An automatic performing apparatus and an electronic instrument with which a user can carry out an automatic musical performance, even for a complicated arrangement, simply by providing external events at certain intervals or corresponding only to a melody. In such an electronic instrument, at the time of execution of the automatic musical performance, the keyboard events are provided at intervals of one beat. Then, the automatic musical performance is progressed within a certain section corresponding to each of the provided keyboard events. Otherwise, at the time of execution of the automatic musical performance, the keyboard events are provided at the timing of a melody. Then, musical tones for the corresponding melody are generated, while those for accompaniments following the melody are also automatically generated. Furthermore, the tempo of the automatic musical performance is set on the basis of intervals between the keyboard events.