This study aimed to assess the effect of musical training in statistical learning of tone sequences using Magnetoencephalography (MEG). Specifically, MEG recordings were used to investigate the neural and functional correlates of the pre-attentive ability for detection of deviance, from a statistically learned tone sequence. The effect of long-term musical training in this ability is investigated by means of comparison of MMN in musicians to non-musicians. Both groups (musicians and non-musicians) showed a mismatch negativity (MMN) response to the deviants and this response did not differ amongst them neither in amplitude nor in latency. Another interesting finding of this study is that both groups revealed a significant difference between the standards and the deviants in the response of P50 and this difference was significantly larger in the group of musicians. The increase of this difference in the group of musicians underlies that intensive, specialized and long term exercise can enhance the ability of the auditory cortex to discriminate new auditory events from previously learned ones according to transitional probabilities. A behavioral discrimination task between the standard and the deviant sequences followed the MEG measurement. The behavioral results indicated that the detection of deviance was not explicitly learned by either group, probably due to the lack of attentional resources. These findings provide valuable insights on the functional architecture of statistical learning. (Contains 5 figures.)