I've run many tests with audio/music in CocoonJS and additionally in Appmobi. I have a children's book with BGmusic + 2 stories with 38pages each page with narration (10-25sec).
With R100 I have the BGmusic working great, but unfortunately the looping is not a feature, so the hack/solution for this is to make a timer: manually start the BGMusic in every X minutes, where X = lenght of zhe BGMusic. It works!
For the narrations I used to play them as Sounds, but I have very late or no narration start for first time I go to a page. When I second time go to a page it started, but not played trought the end, but for about 10 seconds.
The solution were to use the preload action in C2, if I preload on start of layout the narrations, they start to play immediately on a page, and they play trought the end. Hurray! :)
The test was done with preload the first 4 narrations, but I have 2x38pcs of them, so did a for loop for preload all of them. Well, the app starts, the custom loading screen loads the content, and when the preload starts CocoonJS Launcher seems to get busy... but I can capture the last action in it. It seems to PRELOAD the 28nd narration, than it freezes.
I think the next step shuold be to make a smart preloading logic for myself: preload the next 2-5 narrations, and keep preloaded the last 1-3 of them, and in every page unload all of the others to keep the memory usage low. I think that this 4-9 preloaded sounds shouldnt make memory problems, but keeps the sound playing stable.