What does 'coll'ottava' indicate in music terminology?

'Coll'ottava' is a musical term derived from the Italian language, meaning "with an added octave." This instruction tells performers to play or sing notes at an octave higher than written. It is a way to indicate that the melody should be transposed up an octave to achieve a brighter or fuller sound.

This technique emphasizes a passage, making it potentially more prominent or expressive. It helps to create various textures and colors in the music, allowing the performer to interpret the dynamics and emotional intent of the piece more effectively. In this context, 'coll'ottava' directly impacts the pitch rather than any other element such as instrumentation, dynamics, or tempo changes, which is why it is regarded as the correct choice in this instance.