Abstract: A derivative work is encrypted using master keys generated from source data extracted from digital sources used to create the derivative work. A software application permits a mix artist to encrypt and stream a derivative work to a worldwide web server, where it is made available to consumers. A software application permits the consumers to acquire and decrypt an encrypted derivative work if the consumer has possession of a corresponding digital source for each of the digital sources used to encrypt the derivative work.

Abstract: A derivative work is encrypted using master keys generated from source data extracted from digital sources used to create the derivative work. A software application permits a mix artist to encrypt and stream a derivative work to a worldwide web server, where it is made available to consumers. A software application permits the consumers to acquire and decrypt an encrypted derivative work if the consumer has possession of a corresponding digital source for each of the digital sources used to encrypt the derivative work.

Abstract: A telephone is provided with a means for automatically generating ringing tones to be heard by a user over ambient noise and in spite of any muffling environment in which the telephone may be located. The ambient noise is measured to determine its amplitude and frequency characteristics and appropriate amplitude and frequency characteristics of ringing tones to be heard by a user over the ambient noise are calculated and generated. The degree to which the ringing tones are muffled by the muffling environment is calculated and suitable amplitude and frequency characteristics of further ringing tones necessary to be heard by a user in spite of the muffling environment are calculated and further ringing tones having the suitable amplitude and frequency characteristics are generated.

Abstract: An apparatus and method for maintaining records in a telephone directory involves maintaining a personal directory of at least one record associated with at least one party with which a telephone call is conducted. The record has a field for identifying the party and a frequency of use field for storing a number representing the number of times a call is conducted with the party. In response to a call conducted with a party, the personal directory is searched for a record associated with the party and upon finding such a record, the contents of the frequency of use field of the record are incremented and the records of the personal directory are sorted in an order dependent upon the contents of the frequency of use fields.