Else / Else If not working

This code runs when i click on a piece of text. The first if works, but the second doesn't want to execute.

if (music = true) {
    music = false;
    $('#musicButton').html("Music: Off")
}
if (music = false) {
    music = true;
    $('#musicButton').html("Music: On")
}

I tried else if and else, but none seem to work.