Conrad, Joan Baez has always been quite forthright about describing herself as primarily a politician who just happens to also be a singer. Her concerts are definitely crafted to present her political point of view which is based primarily on nonviolence and working for peace. (that would be considered "leftist" in some quarters, but it would probably be considered "rightist" in China)

She is not censoring other points of view in presenting only her own views in a concert, she's simply presenting her own views, that's all. She'd be censoring other points of view if she got elected and helped pass a law prohibiting views other than her own.

Expression of one's own ideas is not censorship of other people's ideas.

If Anne Coulter were a singer, she could give musical concerts presenting her political point of view. Alas! She is not. ;-D Therefore she is limited to talking on TV or radio and writing books and articles to present her point of view.