Michael Tanner's interesting and wide-ranging essay raises a large number of issues: how the discontinuity of musical experience with the rest of our experience is compatible with music's importance to us; whether music is a language or a set of languages; whether our musical vocabulary, by itself or in conjunction with our non-musical vocabulary, enables us to characterize our experience of music adequately; what the relation is between technical and non-technical characterizations of music, and how important each of these is in the appreciation of music; what it is for a musical work to be fully coherent, and whether the coherence of one part of a work with the rest of the work can be established by musical analysis; what the understanding of music consists in and whether there are different kinds of understanding of a musical work; what determines the musical value of a piece of music. I shall not be able to take up each of these issues. I shall concentrate upon one of the topics that lies at the heart of the aesthetics of music: the nature of the experience that a listener has if he hears a musical work with understanding. And I shall begin by making two general points about the somewhat nebulous and polymorphous concept of understanding music. These points do not go against any of Tanner's suggestions – on the contrary, they are congenial to his approach.