FOREWORD
ISO (the International Organization for Standardization) is a worldwide federation of national standards institutes (ISO Member Bodies). The work of developing International Standards is carried out through ISO Technical Committees. Every Member Body interested in a subject for which a Technical Committee has been set up has the right to be represented on that Committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
Draft International Standards adopted by the Technical Committees are circulated to the Member Bodies for approval before their acceptance as International Standards by the ISO Council.
Prior to 1972, the results of the work of the Technical Committees were published as ISO Recommendations; these documents are now in the process of being transformed into International Standards. As part of this process, Technical Committee ISO/TC43 has reviewed ISO Recommendation R 16 and found it technically suitable for transformation. International Standard ISO 16 therefore replaces ISO Recommendation R 16-1955 to which it is technically identical.
ISO Recommendation R 16 was approved by the Member Bodies of the following countries :
| Austria |
Netherlands |
Sweden |
| Chile |
New Zealand |
Switzerland |
| Denmark |
Norway |
United Kingdom |
| France |
Pakistan |
U.S.S.R. |
| Ireland |
South Africa, Rep. of |
Yugoslavia |
| Italy |
Spain |
|
No Member Body expressed disapproval of the Recommendation.
No Member Body disapproved the transformation of ISO/R 16 into an International Standard.
International StandardISO 16:1975(en)
Acoustics — Standard tuning frequency (Standard musical pitch)
1SCOPE AND FIELD OF APPLICATION
This International Standard specifies the standard tuning frequency (or standard musical pitch).
2SPECIFICATION
2.1The standard tuning frequency is the frequency for the note A in the treble stave and shall be 440 Hz.
2.2This frequency shall be observed as closely as possiDle when tuning musical instruments.
2.3Tuning and re-tuning shall be effected with the aid of instruments producing the standard tuning frequency within an accuracy of ± 0,5 Hz or enabling the frequency of musical sounds to be measured to the same accuracy.
2.4Musical instruments shall be so constructed that, under the temperature and other working conditions specified by the manufacturer, they are capable of being tuned in accordance with the standard frequency of 440 Hz. (To this end instrument manufacturers may find it desirable to use tuning devices having an accuracy equal to or better than ± 0,25 Hz.)