In this article we present an API and a set of Javascript modules for the synchronized scheduling and aligned playback of predetermined sequences of events such as notes, audio segments , and parameter changes as well as media streams (e.g. audio buffers) based on the Web Audio API logical time. The API has been designed to facilitate the development on both ends, the implementation of modules which generate event sequences or media streams as well as the integration of such modules into complex audio applications that require flexible scheduling, playback and synchronization.