Force File Download in Nginx

Hi all,

I have a link field which contains links for MP3 files hosted elsewhere and I want the files to be downloaded by simply clicking on the field rather than doing right click and "save link as".

This is mentioned here http://blog.waterworld.com.hk/post/nginx-pdf-force-download re Nginx. Are there any BOA considerations here or is this just an Nginx issue?

Thanks...