What term is used to indicate playing a melody eight notes higher than written?

The term used to indicate playing a melody eight notes higher than written is "8va," which stands for "ottava" in Italian. The notation "8va" instructs the performer to play the notes an octave higher than what is shown on the sheet music. This is a common practice in musical notation to avoid excessive ledger lines, allowing musicians to play higher pitches more easily and clearly.

In contrast, "8vb," which indicates playing eight notes lower than written, serves a different purpose and is not applicable in this context. Accidentals refer to symbols like sharps, flats, and naturals that alter the pitch of notes, while repetition involves playing a segment of music again, which does not describe the specific instruction to play higher notes. Thus, "8va" is the correct terminology for this directive in music.