An automatic performance apparatus comprising: a storage section configured to store therein a plurality of sets of audio waveform data, wherein each of the sets of audio waveform data has a time range of one or more measures; a reproduction section (8, 1, S3) configured to reproduce any one of the sets of audio waveform data, stored in said storage section, in accordance with passage of time; and a designation section (6, 1, S5) adapted to designate, during reproduction by said reproduction section of a first set of audio waveform data of the plurality of sets of audio waveform data, a second set of audio waveform data of the plurality of sets of waveform data; characterized in that said storage section is further configured to store switchover position information indicative of, for each of the sets of audio waveform data, a plurality of possible switchover positions in the audio waveform data, and said automatic performance apparatus comprises a control section (1, S6, S7, S8) configured to, in response to designation of the second set of audio waveform data via the designation section, specify one of the plurality of possible switchover positions for the second set of audio waveform data on the basis of a current reproduction position in a current measure of the first set of audio waveform data currently reproduced by the reproduction section, and determine switchover timing within the current measure based on the specified possible switchover position, said control section further configured to control (S22, S23) the reproduction section to reproduce the first set of audio waveform data until the determined switchover timing, and to control the reproduction section to start to reproduce the second set of audio waveform data at the determined switchover timing from the specified possible switchover position of the second set of audio waveform data. a storage section configured to store therein a plurality of sets of audio waveform data, wherein each of the sets of audio waveform data has a time range of one or more measures; a reproduction section (8, 1, S3) configured to reproduce any one of the sets of audio waveform data, stored in said storage section, in accordance with passage of time; and a designation section (6, 1, S5) adapted to designate, during reproduction by said reproduction section of a first set of audio waveform data of the plurality of sets of audio waveform data, a second set of audio waveform data of the plurality of sets of waveform data; characterized in that said storage section is further configured to store switchover position information indicative of, for each of the sets of audio waveform data, a plurality of possible switchover positions in the audio waveform data, and said automatic performance apparatus comprises a control section (1, S6, S7, S8) configured to, in response to designation of the second set of audio waveform data via the designation section, specify one of the plurality of possible switchover positions for the second set of audio waveform data on the basis of a current reproduction position in a current measure of the first set of audio waveform data currently reproduced by the reproduction section, and determine switchover timing within the current measure based on the specified possible switchover position, said control section further configured to control (S22, S23) the reproduction section to reproduce the first set of audio waveform data until the determined switchover timing, and to control the reproduction section to start to reproduce the second set of audio waveform data at the determined switchover timing from the specified possible switchover position of the second set of audio waveform data.