Follow along with this link (right click to download from archive.org).
I should note, Jack had used guest hosts before - Herbert Marshall filled in on February 2, 1941 and later Robert Taylor would fill-in on May 16, 1948. There's even an episode where Jack appeared (April 3, 1938), but the show opened with George Jessel hosting - in each of these instances, Jack was deeply resentful when he returned to the studio and found his cast much preferred the guest host over himself. Such is the case again as Jack deals with the four week fill-in Orson Welles delivered.
The show is set in Jack's bedroom as he's supposedly still bed-ridden. This means more of Rochester than usual (as he must nursemaid Jack) and no one ever complained about having too much Rochester! Rochester supplies cough medicine made from gin ("You'll find very few pharmacists with the imagination I've got!") and sets up the toaster in the bed to keep Jack's feet warm. Rochester fields a call from his girlfriend and asks Jack if he can have the night off; when Jack refuses, Rochester invites his girl to the house instead!
As Mary arrives, there's this gem:
Jack: "Rochester, what are you doing with my cough medicine?"
Rochester: "I was holding it up to the light and some of it ran down my throat!"
As Jack insists he has to return to his show, Mary begins gushing over Orson's prowess as a performer; Jack begins to slowly smolder in his bed (and not because of the toaster). Jack grouses, "I was sick in bed for five weeks, he didn't even send me a basket of fruit! I finally had to wire him!" Ah, it's good to have Jack back!
Phil arrives next with a gag about his wife (Alice Faye)'s lousy baking. Naturally, Phil is the one most upset at Orson's exit.
Phil: "Gosh, I'm sure gonna miss Wellesy. Without him the show won't have no refinement, no culture, no class!"
Jack: "It won't have no Harris if you don't shut up!"
When Rochester asks if Benny would like to see his doctor Jack retorts, "No, I've been lying in bed all week because I can't find my pants!" The doctor is played by Frank Nelson, so you can guess he won't be entirely helpful (later in the show Nelson's characters were truly antagonistic towards Jack - at this stage, his characters' attitudes might best be described as apathetic). The doctor keeps making references to his other patients being pets, meaning Jack was too cheap to hire a real doctor.
Jack: "Now Doc, would you mind examining me? I've gotta go down to NBC and do a broadcast today."
Frank: "Why? Is Orson Welles sick?"
After the doctor leaves, Jack and Rochester have one of their famous sing-song exchanges:
Jack: "Oh, Rochesterrr...?"
Rochester: "Yes, boss?"
Jack: "Why are you pouring my cough medicine into those cocktail glasses?"
Rochester: "I thought it might liven up the partyyy!"
Jack's boarder Mr. Billingsley (show writer Ed Beloin) drops in to offer some of his standard non sequiturs.
Jack: "We were just talking about you, Mr. Billingsley, your ears must be burning."
Mr. Billingsley: "Well, I'll have to call the fire department, I've got a new hat on!"
Mr. Billingsley winds up hiding under Jack's bed ("in case your husband comes home") and bumps his head, recalling the previous two weeks' gag of Radcliff (co-writer Bill Morrow) bumping his head. Don and Dennis arrive, setting up a fantastic "I worry about things like that" piece:
Jack: "I have a hunch we're gonna have a pretty good show today."
Dennis: "Without Orson Welles?"
Dennis: "Gosh, the Orson Welles Program without Orson Welles? I worry about things like that!"
Rochester passes around scripts ("everyone gets a script and a glass of cough medicine!"). Miss Harrington (Verna Felton) returns to once again herald the arrival of Orson Welles (this time Mary greets her with "Hello, Slugger."). Miss Harrington begins insulting Jack, much as every other character she portrayed on the show over the decades would. Orson arrives, accompanied by his fanfare and gong.
Orson seems to have more trouble than usual keeping a straight face and all on account of Jack! Orson asks to observe while Jack rehearses the program, to which Jack relents. Upon remarking he doesn't have a chair, Orson is offered Mary, Don, Phil and Dennis' seats, causing Jack to angrily suggest Orson take his bed. Orson thinks comedy is best when unrehearsed and suggests they only rehearse the musical pieces, ordering Dennis to sing his song.
After Dennis' song, Orson insists Jack is in control; Jack asks Dennis to cut half a minute from his song, but Orson objects; Jack relents and suggests Dennis add half a minute, but Orson objects to this as well; Jack tells Dennis to leave it alone, which Orson also objects to, much to Jack's growing anger, at which point he flubs and calls him "Oris," leading to a great ad-lib:
Jack: "It took him ten years to build up the name Orson Welles, I made it Oris in one second!"
Jack follows this up by stepping on one of Orson's lines, to which he apologizes; it's interesting to note how few flubs there were in the previous five weeks, but now that Jack's back - flubs, ahoy! When Don asks to practice his commercial Jack refuses; this causes Orson to intrude again, and he's so enraptured by Grape Nuts that he basically does Don's commercial for him. Unfortunately, during this Jack protests, "But Oswald!" which might have been a deliberate flub; Orson cracks up again and pauses the commercial to say to Jack in an aside, "Now you know I can't louse up the sponsor's name!" By this point, it sounds like most of the cast and audience have lost it and Orson's attempts at getting back on track only lead to more flubs! Glorious, beautiful flubs!
Frank Nelson's doctor returns and accidentally gives Jack a sleeping pill; Orson volunteers to take Jack's place once again!
And so we leave this look back at the five week phenomenon which was "Jack Benny Without Jack Benny." In 1944 Orson Welles made another stab at comedy with his Radio Almanac series, but bereft of Jack's cast and writers, it didn't pan out. Later in 1943, Orson would once again take over another program for a month when he became the featured player on Suspense for four consecutive broadcasts. As he didn't have a program of his own at the time, it was a neat idea for him to usurp two of the most successful shows of the era and both are memorable outings.
I've spent a lot of years listening to old-time radio and the Jack Benny Program is one of the best series; if you ever want some recommendations, drop me a line!