Methods and apparatus, including computer program products, are provided for receiving, at a bidirectional recurrent neural network, a music file preprocessed to include at least one token data inserted within at least one location in the music file in order to enable varying the music file; generating, by the bidirectional recurrent neural network, an output music file, wherein the bidirectional recurrent neural network generates music data to replace the at least one token data; and providing, by the bidirectional recurrent neural network, the output music file representing a varied version of the music file. Related apparatus, systems, methods, and articles are also described.