| U | abbreviation of 'und' (German) meaning 'and |
| Über | (German) over, above, too |
| Übung | (German) exercise |
| Uguale, uguali | (Italian) equal |
| Ugualmente | (Italian) equally |
| Ugualità, Uguaglianza | (Italian) equality |
| Ukelele, Ukulele | a guitar-like instrument originating from Hawaii |
| Ullogaun | Irish lament |
| Ultimo, Ultima | (Italian) last |
| Umano, Umana | (Italian) human |
| Umkehrung | (German) turning round, reversal, inversion |
| Umore | (Italian) humour |
| Umstimmen, Unstimmung (noun form) | (German) to tune in a non-standard manner, viz. scordatura |
| Un', una, uno | (Italian) a, an, one |
| Un, Une | (French) a, an, one |
| Und | (German) and |
| Ungebunden | (German) free unconstrained |
| Ungeduld, Ungeduldig | (German) impatience, impatient |
| Ungefähr | (German) about, approximately |
| Ungestüm | (German) impetuous |
| Ungezwungen | (German) easy-going, natural, unforced |
| Ungherese | (Italian) Hungarian |
| Unheimlich | (German) uncanny |
| Uni, Unie, Unis, Unies | (French) united, smooth |
| Uniti | (Italian) united, reunited |
| Unmerklich | (German) imperceptible |
| Un peu | (French) a little, rather |
| Un poco, Un po' | (Italian) a little, rather |
| Unruhe, Unruhig (noun form) | (German) disquiet, without peace, restless |
| Unschuldig | (German) innocent |
| Unten, Unter | (German) under, below |
| Ursprünglich | (German) original, originally |
| Urtext | (German) 'original text', an edition giving the composer's intention free of later editorial additions |
| U.S.F., U.S.W. | German abbreviations; und so fort, und so weiter, and so forth, and so on |
| Ut | the original name of the key-note of a major scale - now generally called 'do' (sometimes 'doh') |
| Uvula | the fleshy area of the soft palate at the back of the mouth |