The US Library of Congress has introduced Citizen DJ, a project currently under development that promises to let you make sample-based music using the Library’s public audio and moving image collections.
The LoC site says:
Citizen DJ is a project by Brian Foo currently under development during his time as an Innovator-in-Residence at the Library of Congress. It invites the public to make hip hop music using the Library’s public audio and moving image collections. By embedding these materials in hip hop music, listeners can discover items in the Library’s vast collections that they likely would never have known existed. For technical documentation and code, please see the repo
Needless to say, you are under no obligation to make hip-hop. : )