I remember seeing the cartoon segment produced by the Hubleys where a voice asks a face if it knows the letter S and the face reveals to be that of a snake. I have noticed something about the snake's voice. Could the snake have been voiced by William "Rosko" Mercer, who also narrated "The Queen of Six", "The King of Eight", and also voiced Limbo in one of the early computer-animated counting segments? He did sound familiar.
I remember seeing some episodes of Sesame's 39th season on channel 10 when I was little, and each time when Elmo's World starts, the black borders are activated for the page turn on widescreen segments. For example, after "Are You Brighter Than an Egg Layer," the black borders appear for "Elmo's World" to start. I wonder why's that??
Muppet Wiki only confirms a handful of performers in the Adventure number. I was watching last night, and I really don't think Jerry Nelson was performing the Count, though his voice is heard. I'd also be surprised if Frank Oz did Grover there. Don't know who did Ernie, the performance looks familiar, as does the purple Honker's. But I'm sure I saw the puppeteering from those performers on so many characters. I actually keep wanting to say that the purple Honker was Kevin Clash, but I would assume that if Kevin was there, he would have performed Elmo (though it's confirmed that he performed Little Chrissy and not Elmo in Gospel Alphabet).
Considering that Sesame Street: 20 and Still Counting aired on a Friday night, known as the "friday night death slot", and was in the same time slot as The Jim Henson Hour, which was known for having low ratings (seems it was often last in its timeslot and among the lowest ratings for the week), I have often wondered if the 20th anniversary special had poor ratings as well or if those were better. Tonight I came across a website showing the TV listings for each date in history (since 1950), mainly listing prime time programming for each night (I think 8PM-11PM) on the non-cable and non-PBS stations, and noticed for many programs it listed ratings. So I checked the programming of April 7, 1989, and see that 20 and Still Counting's ratings were 7.7. Then I checked the premier of The Jim Henson Hour and the ratings were about identical (and then were lower in the following weeks).
Not really sure how to determine how good the ratings are, or if it should be judged more based on which night. I did see that the other programming on other channels typically had better ratings. But it led for me to search the dates for pretty much every Sesame Street special that premiered in prime time outside of PBS, and 20 and Still Counting actually has the best ratings of them all. Of course I am unsure how the website gets its info on ratings for each programming. And not every program on each night is listed, in some cases there is a blank - like on the night of A Special Sesame Street Christmas, there's a blank for the CBS schedule at 8 (which I assume is when that was on), and there's no ratings listed for Elmo's Christmas Countdown or Sesame Street: 50 Years of Sunny Days. There's also a blank for NBC on the date that This Way to Sesame Street at 8 premiered (I assume that aired in prime time and not daytime hours.... would be interesting to see if those ratings were good or not).
I guess maybe Sesame Street is not so successful on network prime time. Though there have been plenty of network Sesame Street specials.