It doesn't matter is audio sources are play on awake or not. It doesn't matter is the game object is active or disabled. Having too numerous audio sources in a world will cause sounds that are play on awake on loading into a world to fail, the sound will play for about half a second, then stop.

I deleted a working piano from my world and everything began working again.

Before and after logs

https://gist.github.com/akalink/84aae8829cf56e02344164990e8a0035