Non-transitory computer-readable storage medium stored with automatic music arrangement program, and automatic music arrangement device

A non-transitory computer-readable storage medium stored with an automatic music arrangement program, causing a computer to execute a process of music arrangement of a musical piece data, the automatic music arrangement program causing the computer to execute:

• a musical piece acquiring step of acquiring the musical piece data by accessing a memory, wherein the musical piece data has a data structure that stores chords and sound production timing corresponding to each of the chords;
• a chord information acquiring step of extracting the chords and the sound production timings of the chords from the musical piece data acquired in the musical piece acquiring step;
• a note name acquiring step of acquiring note names of root notes of the chords acquired in the chord information acquiring step;
• a range changing step of changing a position in a pitch of a pitch range that is a predetermined range of pitches by one semitone each time;
• a candidate accompaniment generating step of generating, for each pitch range changed in the range changing step, candidate accompaniment parts that are candidates for an accompaniment part from sounds of pitches corresponding to the note names which are acquired in the note name acquiring step in the pitch range, and the sound production timings of the chords which are acquired in the chord information acquiring step corresponding to the sounds;
• a selection step of selecting an arranged accompaniment part among the candidate accompaniment parts on a basis of the pitches of sounds included in the candidate accompaniment parts generated in the candidate accompaniment generating step;
• an arranged data generating step of generating an arranged data on a basis of the accompaniment part selected in the selection step;
• and
• an arranged data displaying step of displaying a simplified musical score having fewer chord with respect to a musical score corresponding to the musical piece data based on the arranged data on a display.

An automatic music arrangement device, comprising:

• a display;
• a memory;
• and
• a hardware processor, configured to:
• access the memory to acquire a musical piece data including a melody part, wherein the musical piece data has a data structure that stores a plurality of musical notes, a start time corresponding to each musical note, a sound production period corresponding to each musical note, and a pitch corresponding to each musical note;
• extract, from the musical piece data, the plurality of musical notes of the melody part and the start time, the sound production period and the pitch corresponding to each of the musical notes;
• identify one of a plurality of first musical note having a highest pitch among the first musical notes, among the musical notes extracted from the melody part, as an outer voice note based on the start time of the first musical notes extracted from the data structure of the musical piece data, wherein the start times of the first and second musical notes are approximately the same;
• identify a second musical note of which sound production starts within the sound production period of the outer voice note and of which the pitch is lower than that of the outer voice note as an inner voice note, among the musical notes based on the pitch and sound production period corresponding to the first and second musical notes extracted from the data structure of the musical piece data;
• generate an arranged melody part by deleting the inner voice note from the musical notes extracted from the melody part of the musical piece data;
• and
• generate an arranged data based on the arranged melody part;
• and
• display a simplified musical score having fewer musical notes with respect to a musical score corresponding to the musical piece data based on the arranged data on the display.

An automatic music arrangement device, comprising:

• a display;
• a memory;
• and
• a hardware processor, configured to:
• access the memory to acquire a musical piece data, wherein the musical piece data has a data structure that stores chords and sound production timing corresponding to each of the chords;
• extract the chords and the sound production timings of the chords from the musical piece data acquired by the musical piece acquiring portion;
• acquire note names of root notes of the chords acquired by the chord information acquiring portion;
• change a position in a pitch of a pitch range that is a predetermined range of pitches by one semitone each time;
• generate, for each pitch range changed by the range changing portion, candidate accompaniment parts that are candidates for an accompaniment part from sounds of pitches corresponding to the note names which are acquired by the note name acquiring portion in the pitch range, and the sound production timings of the chords which are acquired by the chord information acquiring portion corresponding to the sounds;
• select an arranged accompaniment part among the candidate accompaniment parts on a basis of the pitches of sounds included in the candidate accompaniment parts generated by the candidate accompaniment generating portion;
• generate arranged data on a basis of the accompaniment part selected by the selection portion;
• displaying a simplified musical score having fewer chord with respect to a musical score corresponding to the musical piece data based on the arranged data on a display.