I made a texture and it's not working I made an image with text and drawings to simulate play pause and other audio buttons and made it black for using it like a mask; where one material is shown through the image and other material from everything else. However, it only shows one material and even using it like a normal image texture through the diffuse or something isn't working and doesn't show. I made it before with other renders and never had this problem if it is important I'm using blender 2.79
Your mix shader mix input should be feeded by alpha output of the texture, not from the color output (which gives you 0.0 for black and 0.0 for transparency).

Enable node wrangler addon and Ctrl click on nodes to see their output and check the nodes workflow.