One or more attributes (e.g., pan, gain, etc.) associated with one or more objects (e.g., an instrument) of a stereo or multi-channel audio signal can be modified to provide remix capability. In some implementations, a method can include obtaining a first plural-channel audio signal having one or more objects; obtaining side information, at least some of which represents a relation between the first plural-channel audio signal and the one or more objects; obtaining a set of mix parameters; and generating a second plural-channel audio signal using the side information and the set of mix parameters.