The following steps should help you to embed any Music Plugin player in your blogs on Blogs Plugin.
1. Goto http://musicplug.in/
2. Choose the song you like to add to your blogs.
3. While clicking on the song, pop-up window will open in which musicplugin player plays the song.
4. If you scroll down, you can notice embed-code and next to that text-box/button, click on that and copy it to your clipboard.
5. Login to your Blogs Plugin account, edit the post where you want to insert the player code. Remember to switch to HTML mode (and not Visual mode) in the blog text editor. Then paste the code in the desired location in the text editor.
6. Save the blog.
The above steps should help you to display the player correctly in your blog.