Seems like it to me but I wonder what others think. He sounds too good ,he’s 83 here. The young guys are singing live.
I say it was genuine singing, but I only watched through Frankie Valli’s first part. It looked a little sketchy when he started singing, but I say genuine from what I saw.
Sounded to me like he had one of those T-Pain Auto-Tune microphones (I assume it’s built into the mike) turned way up.
Wow, I honestly read the title as Frankie Vanilli. The “lip synch” part influenced my mind.
Considering that he only soloed on two lines and didn’t attempt to go falsetto, I’m included to think it was live.
Dude’s 83. The fact that he can walk out on stage without assistance is enough for me.
My teen daughter loves Frankie Valli and I brought her to a concert a few years ago. She was thrilled and stated “he sounds just like his records” I was like … um yeah because he was totally lip syncing but the 4 seasons were not. I really noticed it when he talked to the audience and then would break out into a song. His speaking voice was gravely and low and slow.
He’s been pretty open for the last I don’t know how many years about the fact that he doesn’t have the range he used to and that his young hired guns do most of the heavy lifting now. I haven’t seen him in person, but I’ve seen live videos and he seems to act more like an Emcee who sings on the less demanding parts. He still seems to be a good front man even if others do much of the lead singing.
I say it’s real but enhanced. Still pretty good considering his age. I don’t blame the OP for being suspicious.
I always liked Frankie and the Four Seasons. A lot!!! 
Agreed. I thought he walked like a man.
mmm
That is what I heard: T-Pain Autotune Mr. Mic. There was some heavy processing done on his vocals.