Playing an MP3 through Ruby on Rails in chrome using send_file

I’m writing a Ruby on Rails application which allows a user to upload an mp3 file, then play it back. I have it working to the point where a user can do those things, BUT there is an issue when seeking through the song. If a user seeks ahead (or lets it play) to a spot in the song, usually about 2/3 or 3/4 the way through the song, then attempts to seek back to the beginning (for example 0:20), the play timer will go to 0:20, like it should but the actual audio will start over again as if the user seeked to 0:00.

Right now I’m simply attempting to get the song to play in chrome’s basic html5 mp3 player that it uses when passed an mp3 file. This is the code I’m using to serve up the file, hopefully with all the correct headers:

http://privatepaste.com/8406f69836

I think it has something to do with send_file not adhering to the Content-Range headers.I’d appreciate any insight into this problem. I feel like I’m so close because it pretty much all works, except for seeking near the beginning causing a new request.
Thanks!