ISMN
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "ISMN".

The International Standard Music Number or ISMN (ISO 10957) is a ten-character alphanumeric identifier for printed music developed by ISO. It consists of four blocks: the prefix M to distinguish it from ISBNs, a block to identify the publisher, another to identify the item and one final check digit. The TC 46/SC 9 is responsible for the standard.

A publication may be assigned both an ISBN and an ISMN. Unlike the ISBN, the ISMN does not segregate publishers by country.

To calculate the check digit, each digit of the ISMN is multiplied by a weight, alternating 3 and 1 left to right. The letter M counts as 3. These weighted digits are added together. The check digit is the integer between 0 and 9 which makes the sum a multiple of 10.

For instance, for the item with ISMN beginning M-060-11561:

3xM + 1x0 + 3x6 + 1x0 + 3x1 + 1x1 + 3x5 + 1x6 + 3x1 =
 9  +  0  +  18 +  0  +  3  +  1  +  15 +  6  +  3  =  55

as the check digit is 5 and the full number M-060-11561-5.

External links

• International ISMN Agency