To change the existing address bar/favicon in Slide WordPress Music Theme, or if you want to add your own favicon, please navigate to Appearance – Customize (or use the Customize link from the admin bar) and select Site Identity option. There, you can set the website title, website tagline and the favicon. We recommend using a 512 x 512 pixels image for your favicon.
Please check the video below for better understanding:
The favicon should now be visible – please check the screenshot below to see the favicon applied: