The dataset contains EEG recordings from three groups of infants (4 months old, 8 months old and 12 months old) while they listened to a three note musical melody. There are 52 infants in total (18 x 4-months olds, 17 x 8-month olds and 17 x 12-month olds). The data set is in the form of 3 dimensional matrix with 128 EEG channels x 250 time points x 360 trials.