All'ottava (Italian; all'ott. Or 8 va ) - indicates the performance of a musical phrase against the one written by the octave above. Returning again to its former height is indicated by the word loco. In the scores, all'ottava shows that this instrument should be one octave ahead of the other. And under the notes of the bass this mark happens, but then it means that we need to take an octave below. It would be more correct to write coll'ottava bassa in this case.
Literature
- All'ottava // Brockhaus and Efron Encyclopedic Dictionary : in 86 volumes (82 volumes and 4 additional). - SPb. , 1890-1907.