This paper deals with the problem of managing multiple multimedia streams in a Web environment. Multimedia types to support are pure audio, video with no sound, and audio/video. Data streams refer to the same event or performance, consequently they both have and should maintain mutual synchronization. Besides, a Web player should be able to play different multimedia streams simultaneously, as well as to switch from one to another in real time. The clarifying example of a music piece encoded in IEEE 1599 format will be presented as a case study.