Thu, May 30, 2013 12:41 PM EDT

Alice Walker and Alicia Keys are two well-known black female artists whose work exists in very different worlds. Walker is a renowned author and outspoken activist and Keys is a Grammy-winning recording artist. That's all to say that, generally speaking, their paths don't cross much. But on Wednesday, Walker released an open letter to Keys in which she tries to get the singer to consider the political consequences of an upcoming performance in Israel. And she throws some serious shade.

Walker writes: