From a study by Tikhomirov AM, and Vitvitskaia LV:
Stimulation of salmon larvae by electric current led further to unstable character of reactions in the open field. Acoustic stimulation both by tonal and musical signals favourably influenced the behaviour in the open field and the ability to elaborate conditioned reflexes. Changes of the content of nucleic acids were not found in the brain tissue but were found in the muscles, where they correlated with the growth speed and motor activity of the experimental fishes. The obtained data show the possibility of elaboration of applied methods of the control of CNS development and behaviour of young fishes at fishing plants.
Hand Colored Enraving of a Salmon, 1785-1794
Baron Carl Von Meidinger
In this study the researchers find that not all the changes in listening to classical music take place in the brain, but in the case of these salmon fry, in the muscles, in both speed of growth and their general levels of activity. This provides interesting speculation about the effect classical music may have in children and muscular development. A survey of children who grew up listening to classical music and their muscular growth, compared to children who did not hear classical music, might provide some interesting results. In any case, it seems clear that the benefits of classical music extend beyond the brain!