Mark LeVine is a professor of history at the University of California: Irvine, and author, most recently, of Heavy Metal Islam: Rock, Resistance, and the Struggle for the soul of Islam (Random House 2008) and Impossible Peace: Israel/Palestine Since 1989 (Zed Books, 2009).

"My music may be soft, but I'm a warrior on stage."

So explained Tunisian folk rock singer Emel Mathlouthi as we sat in the restaurant of the African Hotel after almost eight hours of rehearsal for a concert she performed at the Museum of Carthage two days later. It was a defiant remark, coming in response to a discussion of the much-celebrated role of hip hop in the Tunisian revolution, and Mathlouthi certainly had a point.

Rappers like Tunisia's El General have received hundreds of thousands of YouTube hits and repeated international attention for writing their songs supporting the revolution. But watch Mathlouthi's rendition of "Kilmati Houra" (My Word is Free), which she performed on the street on amidst the crowd on Bourghiba Avenue on a chilly winter's evening in the middle of the revolution, and the power of a simple voice, without drum machines, effusive anger and the other aspects of hip hop, becomes clear.

On the Street, but not of the Street?

There are many reasons Arab hip hop has become one of the defining cultural motifs of the revolts of the last eight months. It's gritty, angry, and evokes the kind of urban imagery - poverty, unemployment, police brutality, lack of life chances - that were at the heart of hip hop culture before it was taken over by bling. Today, Tunis, Cairo and other Arab capitals have, in one sense, inherited the mantle of Compton, Oakland or Brooklyn, where much of the most famous political American rap emerged.

In contrast, Mathlouthi's songs recall the generation prior, reminding us of folk music's powerful role in the American civil rights and anti-war struggles of the 1960s and 1970s. And so it was not surprising that as we talked about the evolution of her music, she turned to singers like Joan Baez and Bob Dylan before I could mention them.

"At first, I had rock band and we played covers of hard bands like In Flames, the Dark Tranquility, The Gathering and Italian gothic group Lacuna Coil. But then I switched to softer music after listening to Baez and Dylan, and realised what you could do with just a guitar and voice. My music became more revolutionary as it became softer."

Mathlouthi's insight about the power of softness struck a chord with me, as it mirrored precisely the experience of Egypt's Ramy Essam, another metalhead turned acoustic singer who became one of the main voices of Tahrir Square.

Already sold on the importance of hip hop to the Tunisian revolution, when I first heard Essam's version of his soon to be famous song "Irhal" ("Leave Now!" the Egyptian equivalent of the ubiquitous slogan "Dégage!" In Tunisia), featuring just him singing over his acoustic guitar, I immediately called a producer friend to work on a hip hop remix with drums and bass. To my ears, they would help turn a great protest song into a revolutionary anthem. But as soon as I watched the crowd react to him performing it live in Tahrir a few days later it became clear that the extra instrumentation were superfluous....