[Plugin: NextGEN Gallery] NextGen Monoslideshow Music

HI Im trying to add music to the following slide show:

https://myoverlandadventure.com/photos/croatia/

I have added the custom field to the page as follows:

Name: ngg_ir_Audio
Value: https://myoverlandadventure.com/wp-content/Music/Coldplay%20Clocks.mp3

The page its self simply has the embed code in its body:

[nggallery id=11]

Even though the link seem to work, i do not get any sound, could any one point me in the right direction.

Many thanks

Martin