This paper presents a mobile audio server enhanced with personalization capabilities. The server as well as the client is implemented over the Android platform. It provides mobility to the system’s parts. The metadata which support personalization are separated into two categories: the metadata describing user preferences stored at each client and the resource adaptation metadata stored at the server. The multimedia models MPEG-21 and MPEG-7 are used to describe metadata information. The Web Ontology Language (OWL) is used to produce and manipulate the relative semantic descriptions about the metadata. The mobile server promotes audio tracks to the clients according to their preferences.