keySocket.init(
    "youtube.music",
    function (key) {
        if (key === keySocket.NEXT) {
            var nextButton = document.querySelector('#left-controls > div > paper-icon-button:nth-child(3)');
            keySocket.simulateClick(nextButton);
        } else if (key === keySocket.PLAY) {
            var playPauseButton = document.querySelector('#left-controls > div > paper-icon-button.play-pause-button.style-scope.ytmusic-player-bar');
            playPauseButton.click();
        } else if (key === keySocket.PREV) {
            var backButton = document.querySelector('#left-controls > div > paper-icon-button:nth-child(1)');
            keySocket.simulateClick(backButton);
        } else if (key === keySocket.STOP) {
            var stopButton = document.querySelector('#left-controls > div > paper-icon-button.play-pause-button.style-scope.ytmusic-player-bar');
            stopButton.click();
        }
    }
);

@@ -186,21 +186,20 @@
 tton
-:nth-child(3)
+.next-button
 ');%0A
@@ -412,39 +412,8 @@
 tton
-.style-scope.ytmusic-player-bar
 ');%0A
@@ -591,21 +591,24 @@
 tton
-:nth-child(1)
+.previous-button
 ');%0A
@@ -816,39 +816,8 @@
 tton
-.style-scope.ytmusic-player-bar
 ');%0A

Fix YouTube Music controls