Help editing blown out/poorly recorded audio from a concert?

[+Audioboxer Subscriber²]

Hey guys, I was at a concert last night and recorded some videos on my Nexus 4. Video is great but audio is horrific. I was right down the front of a loud concert, even resting my hands to stabilize phone on some of the feedback speakers.

As expected the audio recordings are pretty unlistenable, and frankly sound terrible. Is there anyway to salvage them a little by sorting out some clipping or lowering certain aspects of the audio? (bass blows everything out substantially).

My internet speed is pretty poor so I haven't uploaded anything to show you yet, I can do that, in the meantime though any free or opensource program recommendations that could help me would be good :)

Thanks