A portable music player apparatus that outputs visual content to a
head-worn transmissive display, the visual content being modulated in
time with playing musical content and overlaid upon the user's direct
view of his or her physical surroundings. In this way, the user is
provided with an enhanced visual view of his or her physical
surroundings, the enhanced visual view including transmissive visual
content that is generally synchronized in time with the playing music
content. This provides the user with an improved music listening
experience in which he or she feels present within a visually enhanced
version of the physical world that has changing visual qualities that are
perceptually synchronized in time with one or more features of the
playing music. The displayed visual content may include time-varying
translucency and/or color-tinting such that the user's direct view of the
physical world changes in brightness and/or color tinting in a manner
choreographed with the playing music.