| Singular | Plural | |
|---|---|---|
| Nominativ | harmonica | harmonicae |
| Genitiv | harmonicae, harmonicai | harmonicum, harmonicarum |
| Dativ | harmonicae, harmonicai | harmonicis, harmonicabus |
| Akkusativ | harmonicam | harmonicas |
| Ablativ | harmonica, harmonicad | harmonicis, harmonicabus |
| Vokativ | harmonica | harmonicae |