In Kabyle Berber there are two types of plural: one is internal and the other is external. The internal plural is characterized by the fact that the quality of the vowels changes, whereby the last vowel is always A, e.g., azarәz ‘cord’ → izuraz ‘cords’. The external plural involves the suffixation of -n, e.g., iθβir ‘pigeon’ → iθβir-n ‘pigeons’. Kabyle plural presents some melodic items which are not present in the singular form (e.g., iðmәr ‘chest’ → iðmar-n ‘chests’, iðw ‘horn’ → iәiw-n ‘horns’, amәçsa ‘shepherd’ → imәçsaw-n ‘shepherds’). Since they cannot be predicted, these items must be a piece of the root’s lexical properties. For reasons to be determined, they do not appear in singular forms. It is shown that when a root of the external plural class bears an A that is not visible in the singular, this A is promoted to the surface in the plural form at any cost, i.e., even if damage on other items of the root is caused. As a consequence of the appearance of the A, the gemination of a consonant or the expression of a vowel may be suspended, e.g., azәqqur ‘log’ → izәγran ‘logs’. Yet, this A cannot be considered as a plural marker since it may well be absent from external plurals, e.g., argaz ‘man’ → irgaz-n ‘men’. Rather, it is an idiosyncratic property of the root, and the plural morpheme contains an explicit instruction for it to appear on the surface, involving, as it will be shown, a branching phenomenon. Thus, part of the plural morpheme consists in an instruction for a specific melodic item to branch.