In some embodiments, a method includes receiving, at a device, digital audio content to be converted by a digital-to-analog converter to produce analog audio content. The digital audio content has at least one audible frequency. The method also includes selecting, at the device, a first signal and a second signal to output with the analog audio content. The first signal has an inaudible carrier frequency and a bandwidth, and the second signal also has an inaudible carrier frequency and a bandwidth. A difference between the first signal and the second signal is an undesired audible signal. The method further includes outputting, from the device, the analog audio content, the first signal and the second signal, such that when the analog audio content is detected by a recording device the undesired audible signal is detected with the analog audio content.

It has been discovered that a dynamic mixed media package with a mechanism for dynamic modification/update provides a media experience to users that exceeds the experience offered by individual media files. A dynamic mixed media package accommodates various types of media and allows for additional media and modifications of existing media. Additional media includes media generated by consumers, such as media derived from a seed media. A seed media is marked and assembled with supplemental media into a package. The seed media is marked to allow performance of various operations, such as identification of the seed media during the lifetime of the package and attribution when the seed media is incorporated into consumer generated derivative media.

A method of identifying a source of media, including: performing the following actions using at least one computer: identifying a plurality of segments arranged to form said media; generating a representative master key (RMK) of said media from the arrangement of the plurality of segments, wherein the RMK comprises a first listing of master identifiers corresponding to the plurality of segments, each master identifier of the first listing of master identifiers identifying a source master of each segment of the plurality of segments; receiving a listing of fingerprints, each fingerprint of the listing of fingerprints having a corresponding identifier that identifies the source of said media, said each fingerprint also including a second listing of master identifiers; and comparing the first listing of master identifiers in the RMK to the second listing of master identifiers in said each fingerprint in the listing of fingerprints to identify the source.