The songs of male canaries are composed of different phrases; a phrase is defined as a segment of song composed by the repetition of the same syllable. When singing alone or in the presence of a male or female conspecific, the number and duration of the songs of male domestic canaries are similar. Despite these similarities, there are differences in the production of phrases between confrontations with conspecifics and singing alone. The presence of another canary, either male or female, induced songs which were characterized by longer strings of A phrases. We have previously demonstrated that this particular phrase elicited many more copulation sollicitation displays in female canaries than other kinds of phrases in the canary repertoire. Thus, the phrase A may be used by the singing males so as to affirm their readiness to interact. By singing A phrases male canaries may communicate both intrasexually (e.g. challenge to male competitors) and intersexually (e.g. courtship of the female). Thus two functions can be linked together in the same signal, the male or female receiver either having different perceptions or giving different senses to the same vocalization.