oktaaveihin
Oktaaveihin is a Finnish term that functions as the illative plural form of the noun oktaavi, meaning octave in music. The form is used to indicate movement toward or into multiple octaves within a musical passage, a vocal range, or a theoretical discussion. While the nominative plural oktaavit is more common for naming octaves in general, oktaaveihin appears in descriptive or analytical contexts to express direction or progression into octave ranges.
Etymology and grammar: The base oktaavi comes from the same root as oktava in many European languages,
Usage: In Finnish music theory and pedagogy, oktaaveihin is used when describing melodic or harmonic movement