Perhaps the greatest thing about music is that it knows no restraints. Musicians explore this vast territory to varying degrees, and with varying levels of success. Some choose to specify, and others choose to generalize. The term "genre" has less and less significance all the time, obvious when you look at the staggering number of sub-niche's we need to describe just rock and roll. Alternative, progressive, pop, punk, funk, fusion, indie, etc., etc.