We had not previously recorded during the first dawn chorus during the playback experiment, which was Perifosine carried out after the dawn chorus. Secondly, from all the males of which we obtained full dawn chorus recordings, we have never detected ‘new’ song types during daytime recordings. Although a limited number of individuals in our population added/dropped song types after confrontation with playbacks or between years, we did not find significant differences between birds that heard their own song or the song of an unfamiliar individual during the playback experiment. Furthermore, the observed changes in the longitudinal study were not related to the presence of new neighbours. We observed however, that the individuals with changes in their repertoire during the playback experiment tended to have a larger repertoire during the first phase of our playback experiment. If social interactions have an effect on repertoire composition during adulthood, great tits should almost permanently change their song types. Moreover, it is well-known that song matching occurs very often in great tits. This would lead to an almost continuous increase or turnover of the repertoire. However, our results conclusively show that this clearly was not the case in our population. Great tits in our population do not appear to change repertoire size or composition as adults and social interactions do not seem to play a role in shaping the repertoire during adulthood. On the contrary, our results rather suggest that the observed changes are linked to large repertoires, which also supports the idea that large repertoires are more easily underestimated, even when complete dawn choruses are recorded. Although there is a lack of laboratory experiments to accurately establish the timing of learning in the great tit, this species was initially assumed to be an age-limited learner. However, previous studies seemed to indicate that the great tits may either be openended learners, which experience a succession of sensitive periods throughout life, or age-limited learners, which are able to recall songs from memory and use the repertoire in a very flexible way, singing different song types in different periods, years or contexts. Our results show, however, that such repertoire flexibility does not exist, at least in our population. Despite the fact that we did not use controlled laboratory experiments, our findings seem to be more consistent with the idea that great tits probably memorise their songs early in life, before the first breeding year and that they do not add songs as adults. Beyond the discussion of being a closed or an open-ended learner, the previous findings on repertoire plasticity in great tits challenged the traditional assessment of song repertoires and the biological relevance of repertoire size as a measurement of male quality. Our study indicates however, that repertoire plasticity, if existing, is very limited, at least in our population.