This, however is contrary to what Gene Simmons has to say about the song. On the Professor Of Rock YouTube channel Gene said,

"Peter does not write songs. He doesn't play a musical instrument. Drums are not a musical instrument, by definition. They're called a percussive instrument. Really important — sometimes extremely important in a band. It was for us. But you cannot play a drum fill that can be copywritten, but you can come up with a riff that you can own and a melody and a lyric. Those can be copywritten, but nothing you do on drums will prevent anybody else from directly copying whatever you did and applying it to another song. Okay, that's number one. Number two, as far as I know, Peter plays no other instruments that I've ever seen. Not keyboards, six-instruments at all. Peter's got a great whiskey voice in the early days. The person who wrote 'Beth' and 'Baby Driver' and one or two more was a guy named Stan Penridge. Stan Penridge was with Peter in a group called Chelsea. They had a record out, actually, I think it was on the MCA. So, Peter did not write 'Beth'. And he did not write 'Baby Driver'. Stan Penridge wrote that. But through politics and — hint, hint, nudge, nudge — and I wasn't there when the conversation went down, Stan Penridge apparently agreed that Peter's name would go in the songwriting credit. It appears first — Peter Criss, Stan Penridge… Or Peter Criss, Bob Ezrin, Stan Penridge, or the other way around. But Peter's first. Peter had nothing to do with that song — nothing. He sang it. And to fix all the mythology and the gossip and the outright lies, it was Bob Ezrin who said, 'I wanna do this like 'Yesterday',' more like a string quartet and piano. So more acoustically, because the melody in the song demanded it. And we'd never done that. We never thought we'd be doing a song like that, but we all went, 'Sure. So, the mythology of 'Beth' is exactly that: mythology. The real story is Peter was lucky enough to be in the same place at the same time as a guy who wrote a song called 'Beth', and then Bob Ezrin, when he heard the song, went home before it was recorded, and then Bob added the middle section of the piano, which was taken legally, as it's public domain. I believe it was a Mozart piano concerto. And that is the story behind 'Beth'."

Doc Reno