If the first two volumes rhythmically fairly House-heavy, so convinced the Volume 4 by more sophisticated melodies, harmonies and rhythms. Even the auditions deal a sunglasses mode because I could not resist and had to get me the same download. The music exudes a great chill atmosphere that even manages to beautify a drab office life. She is also well-suited colleagues (ie it does not take outspoken lovers to listen to this music for a work day can).
What is also important for me: The individual pieces of music are all on the same volume level, so you do not have to readjust and the music quietly sometimes "forget" and can fend for themselves. (Especially useful when you leave his office workstation and sometime later comes back. So no one can complain if a song has even "shouting", while one was not there.)
From me therefore 5 star, and further so - Extraordinary! ;-)