I'm not a tekkie expert by all means, but I think the reason the Loop.ly player won't work on Google pages is possibly because the Google mp3 URL could be coded to work only with the Google player. I grabbed an mp3 URL and uploaded it to Box.com where I have access to the mp3 file's direct URL. I then pasted that into the Loop.ly box and copied the code it produced. I pasted that code into this Blogger post and the Loop.ly player works.
This post is in relation to some Comments here: http://bit.ly/RIVF11
These embeds cannot be done in a Comment on a Post, only in a post itself. So I created a new post for this.