I'm going to copy-paste a page from occupella.org that's too good to lose:

Zipper Songs

Zip in new words to fit your event. We're grateful to the Civil Rights, Labor, Women's and other movements for peace and justice for developing these songs & keeping them alive.

Ain't Gonna Let Nobody turn me around, turn me around, turn me around, Ain't gonna let nobody turn me around, keep on walking, keep on talking, gonna build a better world. Ain't gonna let no corporations…  Ain't gonna let no tuition hikes… Ain't gonna let no pepper spray… (Your ideas here!)

Bella Ciao: Oh we are women, and we are marching, oh bella ciao, bella ciao, bella ciao ciao ciao, We are marching for liberation, We're going to occupy right now! Oh we are artists, and we are weaving (we are weaving for liberation…) Children...dreaming; Poets… singing; Lovers...longing; Mothers...caring; Fathers...crying; Workers...building; Many…demanding; Farmers... planting (we are planting the revolution) People…loving …(Your ideas here!)

Come & Go With Me to that Land, come & go with me to that land, come & go with me to that land where I'm bound. (2x) Single payer in that land… Jobs and justice in that land… Free tuition in that land… (Your ideas here!)

Down by the Riverside: Gonna lay down my sword & shield Down by the riverside. (3x) Gonna lay down my sword & shield down by the riverside, study war no more. (I) ain't gonna study war no more. (6x) Gonna Tell the banks we say no thanks!... We're the 99%...Gonna downsize the Pentagon... Gonna stop corporate welfare…(Your ideas here!)

I'm Gonna Sit at the Welcome Table, (2x) one of these days, Hallelujah! I'm gonna sit at the welcome table, (2x) one of these days… We're gonna:  occupy together… move to a credit union… tax the corporations. . . march the streets together... (Your ideas here!)

Look to the People for Courage in the hard times comin' ahead. Gonna sing and shout, gonna work it on out in the hard times comin' ahead. With people's courage (3x) we can make it. ...for wisdom… humor… singing… (Your ideas here!)
[by Ruth Pelham]

Roll The Union On: We're gonna roll (2x) We're gonna roll the union on. (2x) And if the courts get in the way, we're gonna roll right over them, (3x) If the courts get in the way, we're gonna roll right over them, gonna roll the union on. And if … the scabs... the police... the rich…

Soon and Very Soon we are going to change this world, (3x) Forever and ever we're going to change this world! Time to tax the rich… Equal rights for all… No more corporate welfare… (Your ideas here!)

This Little Light of Mine, I'm gonna let it shine, (3x) let it shine. (3x) Homes & jobs for everyone… Join the credit unions… All around the whole wide world…… All around my neighborhood… All around the workplace… Esta luz mía, voy a verla brillar… (Your ideas here!)

Singing for Our Lives [by Holly Near]:  We are a gentle angry people and we are singing, singing for our lives. (2x) We are a justice seeking people… young and old together … Gay and straight together… (Your ideas here!)

We Are Singing for a Peaceful World: We are singing for a peaceful world, we are singing for a peaceful world. (2x) We are singing (singing) we are singing (singing), We are singing for a peaceful world (2x). We are marching... We are dreaming... We are ready... For the children, for a peaceful world... (Your ideas here!) [from "Siyahamba," South African Freedom Song/new lyrics(?)]

We Shall Not Be Moved: We shall not, we shall not be moved, (2x) Just like a tree that's standing by the water, we shall not be moved! Organize together… At Occupations everywhere… Out with corporate welfare… Bring the soldiers home now… No, no, no nos moverán, (2x) Como un árbol firme junto al rio, no nos moverán... Unidos en la lucha... Basta con la migra… Basta con la guerra… (Your ideas here!)

We Shall Overcome, we shall overcome, we shall overcome some day, Deep in my heart I do believe that we shall overcome some day. We are not afraid… We shall live in peace… We'll walk hand in hand… Justice will prevail… (Your ideas here!)

We'll Be Occupying Wall Street when we come, (Wah hoo!)
We'll be closing down the big banks when we come, (Shut 'em down!)
We'll be ending the foreclosures...(No more!)
We'll be standing with the unions...(Solidarity!)
We'll be standing with the homeless...(Gimme shelter!)
We'll be challenging the power...(Speak truth!)
We'll be saying no to empire...(No pasarán!)
We'll be banking at the co-op...(We own it!)
We'll be voting out big money...(No superPACs!)
We'll be getting single payer...(Say ah!)
We'll be standing with the students...(Save our schools!)
We'll be taxing millionaires...(Vote yes!)
["She'll Be Comin' Round the Mountain," new words by Betsy Rose, exclamations by Nancy Schimmel and Claudia Morrow. Add your own verses.]

When the Poor Have Won Their Rights, oh when the poor have won their rights, oh I want to be in that number, when the poor have won their rights. Oh when the rich pay all their tax…  When every worker has a job… Oh when the soldiers all come home… (Your ideas here!) [tune: "When the Saints Go Marching In"]