On the Robustness of Deep Convolutional Neural Networks for Music Classification

Deep neural networks (DNN) have been successfully applied for music classification including music tagging. However, there are several open questions regarding generalisation and best practices in the choice of network architectures, hyperparameters and input representations. In this article, we investigate specific aspects of neural networks to deepen our understanding of their properties. We analyse and (re-)validate a large music tagging dataset to investigate the reliability of training and evaluation. We perform comprehensive experiments involving audio preprocessing using different time-frequency representations, logarithmic magnitude compression, frequency weighting and scaling. Using a trained network, we compute label vector similarities which is compared to groundtruth similarity. The results highlight several import aspects of music tagging and neural networks. We show that networks can be effective despite of relatively large error rates in groundtruth datasets. We subsequently show that many commonly used input preprocessing techniques are redundant except magnitude compression. Lastly, the analysis of our trained network provides valuable insight into the relationships between music tags. These results highlight the benefit of using data-driven methods to address automatic music tagging.