A method for media processing includes providing a source media clip, which includes at least source audio data, via a network to a client device. A media recording, including client video and client audio data recorded by a user of the client device while playing the source audio data, is received via the network from the client device. The received media recording is synchronized with the source media clip and is mixed with the source media clip to generate a mixed media clip. The mixed media clip is transmitted to client devices over the network for playback by users of the client devices.