Musical Note

In manga and anime, a musical note symbol, or onpu 音符, literally "sound symbol," is sometimes used when there's music in the air. That is, when someone is playing an instrument, or when they're whistling.

Manga: Ashita no Joe あしたのジョー (Volume 1, Page 109)

• Examples
• Vocabulary
• References

Examples

Musical notes aren't really common as a manga symbol. Often, the sound of musical instruments can be represented by onomatopoeia in manga, and in anime you can just literally play the musical sounds.

A case they may still be used nevertheless is when a character is whistling, which can mean they're feigning ignorance or pretending not to know or care about something.

Character: Tenma Gabriel White 天真=ガヴリール=ホワイト
Anime: Gabriel DropOut, ガヴリールドロップアウト (Episode 3)

• Context: Gabriel, after repeatedly trying to turn the air conditioner on and failing, now pretends she doesn't care about it. Instants later, she would attempt to ambush the air conditioner by suddenly pressing the remote control button.
• A 3-shaped mouth is typically used when a character is whistling, by the way.

Vocabulary

For reference, some vocabulary:

• oto
  音
  Sound.
• ongaku
  音楽
  Music. (the art form.)
• kyoku
  曲
  A music. A song. A melody.

Terms for lengths of musical notes use the counter for "parts," bu 分. For example:

• zen'onpu
  全音符
  Whole note. Semibreve.
• ni-bu onpu
  ２分音符
  Half note. Minim.
• yon-bu onpu
  ４部音符
  Quarter note. Crotchet.
• hachi-bu onpu
  ８部音符
  Eighth note. Quaver.
• juu-roku-bu onpu
  １６部音符
  Sixteenth note. Semiquaver.

To say "whistling" in Japanese:

• kuchi-bue
  口笛
  Whistling. (using the mouth.)
  • kuchi
    口
    Mouth.
  • fue
    笛
    Flute.
    Whistle.
  • fu ふ turns into bu ぶ due to rendaku 連濁.
• fuku
  吹く
  To blow air. To whistle

References

• Note Value - en.wikipedia.org, accessed 2020-03-31.
• 楽典解説　音符と休符 - senzoku-online.jp, accessed 2020-03-31.
  • Website of an online school of music. Also contains other musical terminology.