Vreeswijk explained in one of his few interviews that he had taught himself to sing and play in the fifties by imitating his first idols Josh White and Lead Belly.

Influenced by jazz and blues and especially by the singing style and social criticism of Georges Brassens, Vreeswijk "speak-sings" his "insults", and compels his listeners to pay close attention to the words.

His translation of Allan Sherman's masterpiece "Hello Muddah, Hello Fadduh" remains beloved to Swedes as "Brev från kolonien" (Letter from the summer camp) decades later, and could be said to have passed into folklore.

A political singer with a bohemian lifestyle, Vreeswijk remained controversial in the sixties and early seventies, idolized by his fans but disapproved of by many others for his "rude" language and persistent interest in "unsuitable" people like prostitutes and criminals.

During this period, he not only wrote and recorded songs now considered classics, such as "Sportiga Marie" ("Sporty Marie") and several affectionate salutes to the ever less employable "Polaren Pär" ("My Buddy Pär"), but he was an actor on the stage, receiving considerable critical acclaim, most notably as Pilate in the Swedish version of Jesus Christ Superstar, and as Tevye in Fiddler on the Roof.

Spending four months in Brazil began Vreeswijk's lifelong interest in Latin American music and social and political conditions, later seen for example in his Victor Jara album of 1978.

He also became an important musical interpreter of the works of other people, recording the songs of Carl Michael Bellman, Evert Taube, and Lars Forssell.

His fresh, bluesy renderings of Bellman and Taube, who had up to then been classics belonging to the "harmless" tradition that Vreeswijk despised, were artistic and commercial successes which extended his fanbase.

Even though in this period Vreeswijk was a prey of tabloid scandal and in the news for his drinking problem and his debts (about both of which he spoke with frankness) rather than for his achievements, he remained highly productive.

Towards the end of his life his reputation soared again, aided by the televising of some highly regarded nightclub shows, and by Agneta Brunius' TV documentary Balladen om den flygande holländaren (The Ballad of the Flying Dutchman) in 1986.

Because of his long stay in Sweden, though he never became a citizen,[5] the Dutch pronunciation and idiom that he had learned to speak in his youth were out-of-date in the seventies and eighties.