Occupy Guitarmy, an army of musicians who protest with song, marched to Foley Square in New York City for a free concert to mark Occupy Wall Street’s one-year anniversary, which is tomorrow.

The band of guitarists opened with a sing-along of “Wall Street, Your Kingdom Must Come Down” that led into the song, “Frack You,” a song against natural gas fracking set to the Cee Lo Green tune, “Fuck You.”

Tom Morello, Jello Biafra, Das Racist, Rebel Diaz, Michelle Shocked and others are all expected to take the stage from 1:30 pm to 6 pm EST. Morello is scheduled to play around 4 pm EST.

The concert will end with an Occupy Guitarmy sing-along of “Which Side You Are On?” that will be recorded and then go on sale at midnight tonight to raise money for people who are arrested during the anniversary actions.

A version of the song is already posted online. It is a well-produced track with verses written for the Occupy movement like, “Don’t listen to the 1 percent/Don’t listen to their lies/Us poor folk, we got no chance unless we organize.”