A media application for providing outputs (e.g., audio outputs) in response to inputs received from an input device is provided. The media application may connect input mechanisms of an input device with parameters of channel strips (e.g., which may define output sounds) using an intermediate screen object. The media application may first assign an input mechanism to a screen object, and separately map a screen object to a channel strip parameter. The media application may map a screen object to several channel strips simultaneously such that, based on the value of the screen object, the volume of each of the several channel strips changes. The media application may provide a graphical representation of available channel strips using layers. As the media application accesses a channel strip, the appearance of the portion of the layer associated with the channel strip may change.