1. A method comprising: creating a first license comprising a first cardinality, wherein a cardinality indicates the number of playback devices that can be authorized for playback of associated digital audio content, the license created by and the cardinality to be enforced by a license management device; transmitting information corresponding to the first license to a content provider from the license management device; transmitting the first license to a first set of playback devices from the license management device, wherein the first set of playback devices is less than or equal to the first cardinality; storing the first license in the first set of playback devices in response to a command from the license management device; and determining whether playback of first digital audio content received from the content provider is authorized by comparing the first license with the first digital audio content having one or more embedded licenses by the first set of playback devices.