ISMN

The International Standard Music Number or ISMN is a ten-character alphanumeric identifier for printed music. 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.

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

55+5 = 60 is a multiple of 10, so the check digit is 5 and the full number M-060-11561-5.

The ISMN is an international standard, ISO 10957.

External links

• International ISMN Agency