Performance of a single melodic line by more than one instrument or voice is described as playing singing in?

Performance of a single melodic line by more than one instrument or voice is described as playing or singing in unison.

When musicians or singers perform in unison, they produce the same pitch at the same time, creating a unified and harmonious sound. This technique is commonly used in classical music, folk music, and popular music to create a powerful and cohesive musical effect.