This paper proposes a dereverberation method for musical audio signals. Existing dereverberation methods are designed for speech signals and are not necessarily effective for suppressing long and dense reverberation in musical audio signals because: 1) an all-pole model and a non-parametric model, which are used to represent source spectra, do not match musical tones, and 2) the conventional inversefilter-based dereverberation is not effective for suppressing long and dense reverberation. To overcome the two problems, an appropriate dereverberation approach for musical audio signals is established. The first problem is resolved by using a harmonic Gaussian mixture model (GMM) to accurately model the harmonic structure of a source spectrum. The second problem is resolved by performing dereverberation with a Wiener filter based on both an estimated inverse filter and an estimated source spectrum model. Experimental results reveal the effectiveness of the proposed dereverberation met...