At first I thought there was a problem with CDLCs I installed before I got the disc, but after deleting them, or save or update, then trying again, problem still persists:

 

• In RealTone mode, after calibrating and tuning, background lights up, background rock plays for a while, before silencing, after that game is stuck like so completely, but it's not frozen, as output and speakers animation still works:
• After trying aforementioned options, trying to fix it, I've tried Disconnected, but after selecting the song and accepting message about tuning, game freezes completely
• As a last effort, I've used save from Disconnected mode, then switched to RealTone, but after tuning I got a darker version of what you can see above, with output and animations being the only working things.

Disc does not seem to be scratched, my PS3 is fresh out of service, so why just this game does not work?

 

Are you using a modded PS3.

Well, even after disabling mods, these freezes still occur

[solved](somehow) After hearing about this issue, our drummer got an used copy of Rocksmith... 2011, but after playing for a while with it (worth it) and returning to 2014, the newer version works like a charm, even after getting a bunch of CLDCs, which takes ~15 minutes to enumerate them.