Setting
For the most part it is very much the same as our own universe. The main differences include the existence of Music Masters and the amount of causalities and property damage caused by the wars they caused amongst themselves throughout the last century. The peak of these conflicts occur in the 1960's and the 1970's.
In addition, many of history's greatest musicians lived and died as Music Masters. Michael Jackson, Freddie Mercury, Frank Sinatra, Elvis Presley lived and died as some of the greatest.