In recent months, Franki Valli, 90, has raised some concerns. In videos of his live performances, he appeared to miss lyrics and hardly move his lips while singing, prompting allegations of lip-synching.

Valli put out a statement not long after: "I know there has been a lot of stuff on the internet about me lately so I wanted to clear the air. I am blessed to be 90 years old and still be doing what I love to do and as long as I am able, and audiences want to come see me, I am going to be out there performing as I always [sic]. I absolutely love what I do. And I know we put on a great show because our fans are still coming out in force and the show still rocks. ... I get a chuckle from the comments wondering if someone forcing me to go on stage. Nobody has ever made me do anything I didn't want to do."

In a new interview with The Washington Post, Valli again addressed the possibility of him lip-synching: "If I say I'm not, you either believe me or you don't."

Graham Nash and Ann Wilson Aren't Buying It

Some other musicians don't believe Valli, including Graham Nash, who was interviewed for the same Washington Post article.

"Frankie Valli is not singing," he said. "He's just lip-syncing badly to a tape. As a musician, if you're not singing, you shouldn’t be onstage."

Nash, 82, offered up his longtime friend Joni Mitchell as an example of an aging artist utilizing their voice in new ways at live shows, instead of sticking to original notes and arrangements.

"She certainly doesn't have the top-end range that she used to have," he said. "But, at the same time, there is a beauty. What we are getting instead of a top range is incredible phrasing in a lower range."

READ MORE: How Age Forces Rock Singers to Adjust: 'It Happens to All of Us'

Ann Wilson of Heart also provided her reaction and opinion.

"Oh, my God. His face is completely still. He looks like he's not even there. I suppose he's not," she said. "I think that's the moment when you have to decide whether to walk offstage or not. You really have to look at your morals and go, 'Do I just want to go up there and phone it in, give a bulls--- performance because I'm me, or do I take the high road?'"

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Gallery Credit: Ultimate Classic Rock Staff

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