Summarize:

On the left-hand menu, hover over "Plugins" and select "Add New" from the dropdown. " On the "Install Plugins" page, click "Install Now" under the plugin titled "MediaElements.js HTML5 Video and Audio Player." On the next page, click the "Activate Plugin" link. " Once the plugin has been activated, on the left side of the dashboard, hover over "Media", and then click "Add New." You may now find the supported audio file on your PC; click and drag it to the correct box, or you may click the "Select Files" button at the middle of the page to open a window to find your file. Supported file types include MP3, M4A, OGGm, and a couple others " Once your file finishes uploading, click the "Edit" link next to it, when it appears below the file upload box. The "Edit Media" page will open in a new tab on your browser. On the "Edit Media" page, at the right side is a box that says "Save." A couple lines beneath it is a box that says "File URL." Copy the entire URL in the box to your clipboard. [audio src=""] At the upper right of the post/page edit page, click "Save Draft." Then, click "Preview" to see your post or page with the music player as it appears. If you're happy with how it works and appears, go back to the post or page in the editor, and click "Publish" to put your file on the Internet.
Log into your WordPress dashboard. Click "Install Now. Activate plugin. Click "Add New. Upload your file. Click "Edit. Copy URL to clipboard. Navigate to the post or page on which you'd like to add your music player. Type the following in the "Visual" editor: Save and Preview. Publish.