| Jabo | (Spanish) old triple-time dance (original spelling Xabo) |
| Jácara | (Spanish) old song-dance (original spelling Xacara) |
| Jack | a rectangular device, usually made of pearwood, that moves vertically (constrained by the slide and the jack guide) when driven upward by the depression of a key, that bears a small plectrum (usually made of leather, quill or delrin) that 'plucks' the string as it passes it, to produce the characteristic sound of harpsichords, virginals and spinets |
| Jagdhorn | (German) hunting horn |
| Jäger | (German) hunter |
| Jaleadas | (Spanish) a vigorous Seguidillas (a dance) influenced by the cachucha |
| Jaleo | slow triple time Spanish dance, original spelling Xaleo) |
| Jalousieschweller | (German) the organ swell pedal |
| Jammernd, Jämmerlich | (German) lamenting, lamentable |
| Jam Session | an informal performance, originally applied to Jazz |
| Janissary Music (Eng.), Janitscharenmusik (Ger.) | a style of military music associated with the Janissaries, the bodyguard of the Turkish Sultans |
| Japanese Fiddle | a single string instrument seen played by English street performers |
| Je | (German) always, ever, each |
| Jedoch | (German) however, nevertheless |
| Jeu, Jeux (plural form) | (French) game, play, a stop on the organ |
| Jeu de Clochettes, Jeu de Timbres | (French) glockenspiel |
| Jew's Harp (Eng.), Judenharfe (Ger.) | a musical instrument placed between the teeth containing a freely vibrating metal strip that is plucked with the finger and where the player alters the note's timbre by modifying his or her oral cavity (i.e. mouth shape) |
| Jig | (English) gigue |
| Jodelling | yodeling |
| Jongleur | (French) minstrel |
| Jota, La | a dance from northern Spain performed by a couple accompanied by a singer who plays the guitar |
| Jouer | (French) to play |
| Joyeux, Joyeuse | (French) joyous |
| Jubelnd | (German) jubilant |
| Jusqu'à | (French) until |
| Juste | (French) just, exact |
| Justesse | (French) exactitude |