Following the minimal production of their previous album, Human After All (2005), Daft Punk recruited session musicians with the help of Chris Caswell to perform live instrumentation and limited the use of electronic instruments to drum machines, a custom-built modular synthesizer and vintage vocoders. It combines disco, progressive rock and pop, with contributions by Paul Jackson Jr., Giorgio Moroder, Chilly Gonzales, Julian Casablancas, Paul Williams, Caswell, Pharrell Williams, Nile Rodgers, Todd Edwards, Panda Bear and DJ Falcon.