"Unison" is a musical notation used in orchestral scores. It instructs instrument sections to play together in a single voice during a specific passage of music. This notation signifies that in a certain section of the music, where multiple voices or parts might have been playing independently, all instrument sections should now play the same notes simultaneously, creating a unified musical effect.
The concept of unison emphasizes consistency and resonance, allowing all musicians in the ensemble to produce the same pitches at the same time during certain parts of the music. This musical direction contributes to a strong and unified sound, which can be crucial for certain musical compositions and specific musical effects.
In sheet music, "unison" is typically marked as "unis.", reminding performers to play the same notes together during that designated section. This indication can also be used to revert from a divisi (a section split into multiple voices) back to a unified performance.
The use of unison can add power and expressiveness to a musical piece, especially when emphasizing climactic or crucial sections. Composers and arrangers frequently employ this technique to influence the emotions and listening experience of the audience, making the music more engaging and emotionally impactful.