In December of 1964, the Muppets were booked for a guest spot on The Jack Paar Program, a prime-time Friday night talk-variety hour. The Muppet team -- Jim Henson, Frank Oz, Don Sahlin and Jerry Juhl -- arrived at NBC Studios in Radio City for a 10am rehearsal, but they were informed that they weren't actually needed on stage until 4pm. With lots of time to kill, they opened a door in their dressing room and found that it was filled with dark, dusty pipes.
Juhl remembers, in a 1992 interview:
The group decorated the pipes with paint and fake fur, giving the pipes monstrous eyes, goofy noses, and multi-colored faces. Henson later revealed that part of the brown fabric had come from the original Grover.  The team signed the artwork "with LOVE from the Muppets."
As the day went on, Juhl recalls,
By air time, Paar had heard about the project, and brought a camera back into the dressing room to show the audience what the "crazy Muppet people" had done.  The signature at the bottom originally included the phrase "Represented by William Morris" (Henson's agent at the time), but that was painted over in black by the studio before putting it on air. 
NBC told Henson and company that the pipes would be painted over the next day. Since the painting had come about as a lark, and they were just passing time, Henson and the others didn't have a problem with that. However, the next day's painting somehow never happened, and the pipes went largely forgotten about for 16 years.
In 1980, while doing some remodeling in (what was at that time known as) the RCA building, the construction workers discovered the pipes. Though they had been told to knock out everything, the bizarre-looking pipes caught the workers' attention, and they asked NBC for confirmation that the pipes should be removed. After further investigation, it was decided to keep the pipes as they were, and Henson was brought in to film a segment of The Today Show on April 18, 1980 with Gene Shalit, explaining the history of the pipes. Shalit jokingly commented that the pipes would now be kept forever in the building as a museum piece.
In 1984, Jack Paar appeared on Late Night with David Letterman and took Letterman on a tour around the studio to show him the Henson pipes. Paar says, "Now, I never won a lot of awards. But I have something that's so rare, and so touching to me." He later continues, "When I opened this door, you'll see a tribute that was made to me..."
In 1993, the backstage area began being used for Late Night with Conan O'Brien. The pipes were in a closet in Max Weinberg's dressing room. In 2009, Jimmy Fallon took over late-night duties, and he strongly encouraged NBC to make the pipes part of the backstage 30 Rock tour. Fallon displayed the pipes during a satellite interview on The Jay Leno Show on February 12, 2010.
In 2010, Brian Williams brought Frank Oz back to see the pipes for the first time in many years, causing Oz to emotionally comment that he was "the last man standing" from the original group. Soon, Fallon's plan came to fruition, and the pipes were officially unveiled as part of the tour with a "ribbon-cutting" ceremony featuring Oz, Fallon, and Meredith Vieira, once again on The Today Show. Just as Shalit once jokingly predicted, the pipes will now forever be part of the tour as a testament to the creativity of Jim Henson and his business associates.
On November 16, 2011, exactly forty-seven years and one day after the pipes had been decorated, Kermit the Frog was on Late Night with Jimmy Fallon to promote The Muppets. On this day, he visited the pipes to film a brief clip for NBC.com. Just five days later, Walter visited the pipes upon his appearance on Late Night.
On an appearance on The Tonight Show with Jimmy Fallon in March 2014, Kermit and Fallon talked about the pipes and Kermit presented him with a special gift - a specially designed Muppet wrench to take care of the pipes with.
- ↑ 1.0 1.1 1.2 Finch, Christopher, Jim Henson: The Works. 1992.
- ↑ Henson, Jim The Today Show, early 1980s.
- ↑ Oz, Frank NBC Nightly News, 2010