Adding an ottava marking to a single voice

If you have more than one voice on the staff, setting octavation in one voice will transpose the position of notes in all voices for the duration of the ottava bracket. If the ottavation is only intended to apply to one voice, the middleCPosition and ottava bracket may be set explicitly. In this snippet, the bass clef usually has middleCPosition set to 6, six positions above the center line, so in the 8va portion middleCPosition is 7 positions (one octave) higher still.