Putting a playable mp3 file into your website does not require a special plugin. With the new latest version of WordPress, you can now integrate mp3 file and play it right into your web page. Here is a simple and quick way on how to do this.
1. Create a page or go to your existing page/post to where you would like to put your mp3.
2. If you are using Visual Composer, add a TextBlock > Add Media
3. In the pop-up box, click on Upload Files tab > Select Files and upload the MP3 file.
4. Once the MP3 sound file is uploaded , look at Attachment Details at the left and beside Embed or Link, select Embed Media Player. Click Insert into Page then Save the TextBlock.
5. Publish or update the page and play your MP3 in your live site.
Here is a quick video tutorial on how to do this: