Imbedding voice file and music file on one slide

[WilsonJ]

Hello - I'm using PowerPoint 2010 and have recorded voice narration files with external recording software (mp3 files)...one file per slide. I also have one music file I've imbedded on my first slide (along with the voice narration file for slide 1)...(should I think about 'linking' instead?). I'd like the music file to play at a low background level to play throughout all slides. How do I get my music and voice file to play immediately when the show begins....with little to no lapse? I tried Rehearse Timings and Record Narration, but there always seems to be a lapse (the time it takes me to click on the start button after the timer starts). I also cannot see or edit the voice file icon on slide one, but I can see the music file icon. Any and all help will certainly be appreciated!

[JohnWilson]

In the Animation Pane are they both set to WITH PREVIOUS and no trigger. If the sync is wrong you can also give one a slight delay.