Other than sound proofing the house and having dark curtains in his room, I don't think there is much you can do.

Sounds like you might need to put him to bed a little later.  I am having this exact problem except mine has an internal alarm clock that goes off at 5;20.  That's way too early.  But after I feed him, he goes right back to sleep until 8:30.  I don't even know why I am giving suggestions.  Mine will probably throw me off tonight and wake up at 2:30 too.  LOL.  Good luck and hang in there.  They can't be doing this crazy stuff to us 15 years from now, right?  LOL

My boys have always slept till 8am and still do and they go to bed at 7 so really I can't speak from experience only what I would do.

Try putting him to bed at 8pm? See if that works. If it doesn't maybe just go with the flow and let him get up, feed him at 6am and breaky at 7 then try and keep him up as long as possible. I hope you work something out soon.

You should think yourself lucky.... mine starts at 5am!

He goes through stages, sometimes it needs an adjustment of the routine.  In the past I put him down later and that worked but a few months later he went right back to waking at 5 - 6 am again. 

If he is just singing and talking leave him there, he's obviously not wanting for anything and is quite content to hang out by himself.  When my son is insistent on getting up, I get him a juice and some fruit and put cartoons on and doze on the lounge.  It messes up the day but he only goes through it for a little while then goes back to sleeping til 7 again.

Early waking is just one of the many joys of parenting.

As children grow their sleep needs change. You might just be going through one of these changes. He just wants to get up earlier. Just let him play/sing in his room, til he is ready to be up and about, but I think you are going to have change your routine a little.

BTW do you have dark (block out ) curtains in the room. He may be waking to the light??