In October 2009, Amy Goodman, the well-known host of Democracy-Now!, invited the folksinger and songwriter Buffy Sainte-Marie, a Canadian of Native-American descent, to appear on her program. 

Buffy Sainte-Marie has become well-known, even outside North America, as the songwriter and singer  of 'Universal Soldier,' an anti-war song that became widely sung in the early 1960s by those who were not ready to shut their eyes to the minuteman rockets and B-52 bombers circling in the air, heralding the ever-present. absurdly looming nuclear confrontation of the two superpowers. In Britain, quite a few workers in Glasgow's run-down tenement quarters (typical blue-collar neighborhoods!), and of course the Alderston marchers supporting the Campaign for Nuclear Disarmament, were singing "Pull the Yanks down the stanks [i.e. the 'stinks,' the toilets] - we do no want Po-la-a-ris". And they sang "Universal Soldiers." Soon also, the hippies in California took to it, and the "peaceniks" who opposed the slowly escalating war in Vietnam. 

But Buffy's songs also intervened by introducing other themes, like Native American rights, Native American history. Quite clearly she was determined to challenge an 'Anglo' version of American history.  "Correcting names,"  in a way Confucius would have loved. Calling for instance the decimation of the Native population of the American hemiphere what it was - nothing but genocide. As she puts it,

"...most Americans feel that the Indians lost because of fair fights and superior odds and superior weaponry. That’s because that’s the only side of the story that’s been told." 

In Amy Goodman's words, Buffy "was among the earliest if not the first celebrity to challenge the idea that, quote, “American history really began when Columbus set sail out of Europe.”" 

It has to do with her cultural background, her family background. Listen to Buffy:

"I had a Native American background and really interest in knowing what had not been told to me, because when I was growing up, my mother who raised me, she especially told me, you know, what you see in the movies and read in books is not necessarily true, but you can find out someday."

So commitment to Native American rights came almost naturally.

"... I put all my time into Indian rights, and I think this is something I know something about and I think that my time is best spent, insofar as my political views are concerned." 

It affected the way she saw herself as an artist. The 'art' of writing good songs appears to have been an almost 'natural' outcome of her commitment. There was the involvement in her people's history, in a cause. And in the struggle against looming or, in the early 1960s, actual war. It compelled her to write songs, and to do it well. And to sing them herself, and do it well. She "didn't think" she was much of an artist. But she was.

"... you asked, you know, was I was afraid to be onstage. I wasn’t, because of the songs, see? I didn’t think I was much of a singer, but because of the songs, I had the nerve to step out onto a stage and to give the people the songs. So I wasn’t concentrating on myself as a singer. I probably should have been concentrating more. Later on, I learned to sing." 

Yes, with time, practice, experience, a sensibility developing as a result of practice, of practical experience as a songwriter and singer, one can get better. But that's not the main point. 
The main point is, she was good already, though young and not very experienced, in 1961.
Listen to her again: "I wasn't concentrating on myself as a singer"  Dig that! as we would say in the 60s. Have the nerve and make it clear to yourself: the "artist's ego" can recede into the background. And it does - if those she (or he) addresses, and the work that addresses them, matter so much more. And their active reception of the work. By which they appropriate it and make it theirs. And sing it in their own way. And give it their meaning, in accordance with their needs.
 

Source: "Buffy Sainte-Marie. Democracy Now!Special:An Hour of Music and Conversation with Legendary Native American Singer-Songwriter Buffy Sainte-Marie", broadcast on the regular Democracy Now! program on October 12, 2009. Internet source, URL address: http://www.democracynow.org/2009/10/12/democracy_now_special_an_hour_of