Since The Muppets, Steve Whitmire has finally gotten to do the puppetry as well as the voice of Link Hogthrob... And in most of his big speaking scenes, he appears with Beaker, also performed by Steve. Which makes me wonder... Which character is Steve performing in these scenes?
For the "Smells Like Teen Spirit" number, I'm willing to bet that Steve was performing Beaker while another was performing Link, since he'd been performing Beaker for so long, while Link was originated by Jim Henson, previously only voiced by Steve in a few video games (I don't doubt that he might have previously performed the character in non-speaking appearances, or in instances where he spoke but Jim could only perform the voice). Steve didn't have much experience with the character by then, while he's been performing Beaker since 1992, so whether it was him or another performer, they'd be imitating how Jim performed him regardless. And in Muppets Most Wanted, during the "Something So Right" number Link and Beaker get back-to-back lines, both in the same shot/take. I think there's also another scene where both are seen and heard, can't really remember which scene it is.
And just recently, after watching Rock Music with the Muppets so many times on Daily Motion, I've noticed that Dr. Teeth is wearing a white tuxedo vest over his clothes and under his black vest. All this time I thought his 1980s outfit was a black leather vest, but now I wonder if that is actually a tuxedo, with the sleeves cut off, but worn over a striped shirt and white tuxedo vest.