Hugh Downs was already well known as the announcer/sidekick on The Tonight Show during Jack Paar's tenure as host.
Bob Clayton was the host of a short-lived ABC game show, Make a Face, in 1961.
Ed McMahon was, in 1969, known across the country as Johnny Carson's sidekick on The Tonight Show.
Jack Narz, no stranger to the game show genre (Seven Keys, Dotto, Now You See It), was Tom Kennedy's brother (Tom's given name was Jim Narz) and Bill Cullen's brother-in-law.
Alex Trebek was already well-known as the host of Jeopardy! Strangely, he seemed much more intimate than usual on this show. He also had a deer-in-the-headlights look when contestants would snipe at each other.
Ralph Branca, the Brooklyn Dodgers pitcher who in 1951 surrendered the "Shot Heard 'Round the World" home run to New York Giants' Bobby Thomson (sending the Giants to the World Series), was a competitor in 1963 and progressed to the show's first Challenge of Champions.
Johnny Olson and Gene Wood were prolific announcers for Goodson-Todman over many years; Johnny is most well-known for The Price Is Right, while Gene announced the 1976-95 versions of Family Feud.
The show's first announcer, Art James, became an emcee in his own right. He left Concentration in 1961 to host Goodson-Todman's Say When!! and do many more (Blank Check; The Magnificent Marble Machine; The Who, What, or Where Game; Super Pay Cards; Catch Phrase) henceforth. In 1991, things came full circle when he filled in for Gene Wood on Classic for a week.
James also appeared in the film Mallrats; appropriately enough, he played a game show host (Bob Summers) who, unfortunately, could not stop the cast from derailing the show (a ripoff of The Dating Game) with all sorts of stuff (such as Brodie's story of how his Cousin Walter jerked off on a plane).
Keep Circulating the Tapes: Very few episodes from the first 20 years circulate, and no clips have been seen in blooper specials. Because Goodson-Todman (later Fremantle Media) does not own the rights to the show (NBC does), the Jack Narz era hasn't been rerun. None of the other versions has ever been rerun, either, save for Classic from 1991 to 1993 on NBC and for a time on the United Kingdom's Sky One. NBCUniversal has zero interest in either reviving the show or selling repeat rights to GSN (much less anybody).
Episodes from the first 20 years that circulate include October 15, 1958; February 9, 1959 (hosted by Art James and surfaced in January 2012); September 12, 13 and 16, 1963; a 12-minute clip from 1966; September 1967; October 2 and 3, 1967; Christmas Eve 1968; September 1969; Christmas Eve 1969; March 23, 1973; early 1978. Also on YouTube are the last five minutes of a 1974 show and the last two minutes of a 1976 show. Lately, game show legend Wink Martindale has been uploading classic episodes from the Narz-era, with at least two from the 1977-1978 season and another from 1974-1975, none of which have been previously uploaded.
A few shows from spring 1971 are at the UCLA Film & Television Archive, paired up with that day's Sale Of The Century.
Line To God: In February 2011, original series producer Norm Blumenthal started a thread on a popular game show forum, in which he has discussed nearly every detail of the series. However, the thread died out in March 2012.
Missing Episode: According to Blumenthal, most of the original series was wiped. The Narz era onward is intact.
No Budget: Commonly associated with the 1970s Narz version. Usually, there were at least two prizes worth $1,000, and several prizes topped $500, but consolation-type prizes were often main-game prizes (such as boxed spaghetti dinners, Oreo cookies and bar soap); this helped with the low-rent budget (or at least the perception thereof). By the last season, there was an attempt to increase the appeal of the prizes by matching several of the $500-1,000 level prizes together into a single prize package, and then make it available as a prize in the Double Play round's new prize-matching game; $1,000 gift certificates to places like Botany 500 and Western Auto were also common, and some of the prize packages were worth $2,000 or more, and European tours for two worth $4,000 were sometimes offered. Despite the low-level prizes, a lucky contestant winning both rounds and, in the process, matching all the prizes … and then coming away with every prize package available in the Double Play round (there were four per round, one of which was a new car) could have a very nice payday of nearly $20,000.
Everyone remembers the Red and Green Classic Takes. But hardly anyone remembers the one Purple Take that was used for about two weeks between having no Takes and two Takes.
Prop Recycling: Classic's signature car holding staircase was redressed for a set in a special primetime episode/TV movie of NBC's Days of Our Lives while Classic was still in production, but on hiatus.
Screwed by the Network: Lin Bolen wanted to cancel all games hosted by middle-aged men on technologically obsolete sets; on September 4, 1972, CBS replaced daytime repeats of The Beverly Hillbillies with The New Price Is Right, which won over most of the Concentration audience. The first victim of Bolen's agenda, Concentration bowed on March 23, 1973.
To this day, NBC owns the rights to the show and refuses to allow reruns of existing episodes. The show is listed on the network's formats Web site (alongside 21 and Minute to Win It), though.
There were many times during the 1958–78 era where the board "malfunctioned", such as a trilon turning the opposite direction from the others after a puzzle was solved.
The Classic computer board "malfunctioned" in an oddly similar way. Near the end of the run, the last four squares in a game were one prize and two Wild Cards. The contestant matched the prize with one Wild Card, revealing those three spaces...however, a glitch in the program wouldn't allow the last Wild Card to be removed, and it kept flipping back to the number square. Alex commented that "In the four years we've been presenting this show, that's the first time that ever happened!" (Luckily, the contestant was able to solve the puzzle without that one square.)
For a themed week, the Classic set included large neon-lit palm trees. Even after the week was over, the trees stayed because the set designers thought the combination looked cool. After this addition, the set designers decided to go further with the "California Fresh" motif by adding more foliage to the set (especially in the "winner's circle" where the bonus round was played) and letting Trebek be more laid back and dress more casually (often with sweaters).
This car round where things go awry. First, the board revealed the wrong number, so the staff had to stop the clock and reset both it and the board to where they were before the contestant called her numbers. Then, in the last 15 seconds or so, the main monitor went out and she had to squint at a board 30 feet away, losing all her momentum. Alex pointed all of this out to the home viewers and commented that, since he thought she would've won had the technical difficulties not come up, he let her take the car of her choice.
Originally, Alex would insist in the car round that contestants select one number at a time. As the series went on, contestants started selecting two at a time and Alex decided not to fight it.
What Could Have Been: The first idea bantered about was to have drawings of famous people gradually revealed for each match, then just simple phrases. Neither concept worked, and it was through Blumenthal's drawing talents that the rebus puzzle concept came about.