Electronic musical instrument, method of controlling the electronic musical instrument, and storage medium thereof

A method of causing a computer of an electronic musical instrument, which includes plurality of keys that are operable to designate pitches of sound to be output by the electronic musical instrument, to perform a process comprising:

• determining one of the plurality of keys to be a first key, based on pitch information indicating a first pitch of a first timing included in music data, wherein the first key is expected to be designated by a user within a first period according to the first timing;
• determining one of the plurality of keys to be a second key, based on pitch information indicating a second pitch of a second timing after the first timing included in the music data, wherein the second key is expected to be designated by the user within a second period according to the second timing;
• determining at least one of the plurality of keys other than the first key to be at least one third key that is assigned a sound of a different pitch from the first pitch, wherein the at least one third key is determined based on a position or pitch relationship of said at least one of the plurality of keys with the first key;
• displaying an identifier for identifying the at least one third key before the first timing in accordance with progressing of the music data;
• and
• in response to an operation by the user designating the first key or the at least one third key, controlling the electronic musical instrument to output a sound of the first pitch, and progressing the music data from the first timing to a timing before the second timing;
• wherein the processor does not progress the music data from the first timing to the timing before the second timing, when the user designates a key other than the first key or the at least one third key within the first period.

A non-transitory computer-readable storage medium which stores a program that is executable by a computer of an electronic musical instrument, which includes a plurality of keys that are operable to designate pitches of sound to be output by the electronic musical instrument, the program being executable by the computer to control the electronic musical instrument to perform a process comprising:

• determining one of the plurality of keys to be a first key, based on pitch information indicating a first pitch of a first timing included in music data, wherein the first key is expected to be designated by a user within a first period according to the first timing;
• determining one of the plurality of keys to be a second key, based on pitch information indicating a second pitch of a second timing after the first timing included in the music data, wherein the second key is expected to be designated by the user within a second period according to the second timing;
• determining at least one of the plurality of keys other than the first key to be at least one third key that is assigned a sound of a different pitch from the first pitch, wherein the at least one third key is determined based on a position or pitch relationship of said at least one of the plurality of keys with the first key, the program comprising:
• displaying an identifier for identifying the at least one third key before the first timing in accordance with progressing of the music data;
• and;
• in response to an operation by the user designating the first key or the at least one third key, controlling the electronic musical instrument to output a sound of the first pitch, and progressing the music data from the first timing to a timing before the second timing;
• wherein the processor does not progress the music data from the first timing to the timing before the second timing, when the user designates a key other than the first key or the at least one third key within the first period.