Music is a powerful force that evokes human emotions. Several investigations of music emotion recognition (MER) have been conducted in recent years. This paper proposes a system for detecting emotion in music that is based on a deep Gaussian process (GP). The system consists of two parts-feature extraction and classification. In the feature extraction part, five types of features that are associated with emotions are selected for representing the music signal; these are rhythm, dynamics, timbre, pitch and tonality. A music clip is decomposed into frames and these features are extracted from each frame. Next, statistical values, such as mean and standard deviation, of frame-based features are calculated to generate a 38-dimensional feature vector. In the classification part, a deep GP is utilized for emotion recognition. We treat classification problem from the perspective of regression. Finally, 9 classes of emotion are categorized by 9 one-versus-all classifiers. The experimental results demonstrate that the proposed system performs well in emotion recognition.