Icons Not Showing In IOS Device – Solution

HTML

<span class="icon-file-music"></span>

CSS

.icon-file-music:before {
  content: "\e928";
}

CSS Solution 

use height, width, and line-height

.icon-file-music:before {
  height: 20px;
  font-size: 20px;
  line-height: 20px;
 }