Protest music has a long history throughout the world of music. Yet, while it has considerable roots, most only think of its earlier incarnations when it’s mentioned. Artists like Woody Guthrie and Bob Dylan tend to enter folks mind, their acoustic-driven, folk sounds being that which people so often identify with the genre. Yet, while those artists are for sure among the figureheads, protest music has reached much farther than that, seeing it enter into genres as diverse as punk, rock ‘n roll, blues, and even country. And those are the places that anti-establishment musician, Matthew Heller, goes in order to get his message across. The Portland-based artist has plenty to rail against, largely due to his life experiences. The son of a heroin addicted mother, who would eventually fall prey to her addiction, Heller has seen a lot of dark times and his music reflects that. Adding to those experiences, he shares, “I’ve lived in the Mission district in San Francisco, in the Puerto Rican parts of Brooklyn, and in the South Side of Chicago. In Chicago I saw a man freeze to death outside.” Those are the kinds of experiences that color in a life and, in Heller’s case, provide the angst to his passionate artistry. That artistry comes forth in a plethora of forms on Heller’s latest outing, Invitation. One form finds the artist channeling the muse of indie and alt-flavored garage rock as he does on tracks like the energetic “Shake It” and the percussion-heavy “Another Dose.” And with h