The episode of Saturday Night Live aired on April 22, 1978, can stake a legitimate claim to being the best in SNL history. Hosted for the fifth time by a never-better Steve Martin, the episode re-teams Martin with Dan Aykroyd for their strongest “Wild and Crazy Guys” sketch. (The one where the swinging Czech brothers patiently explain to Garrett Morris Cliff that their hot dates are late only because they had to pick up their birth control devices at the Statue of Liberty.)

Martin and Gilda Radner do their deliriously silly and romantic pas de deux to “Dancing in the Dark,” which would be emotionally replayed by a hosting Martin the day Radner died. “Theodoric of York: Medieval Barber” is the template for several Martin-led historical sketches, where his smugly ignorant all-purpose bloodletter, confronted with the carnage caused by his dark ages techniques, posits a grandly enlightened future for science and medicine before hand-waving it with a scornful, “Naaaahhhh.” There was another outing for Radner and Bill Murray’s nerds (this time besting Martin at a science fair), a classic gross-out sketch about the face-first eatery the Troff ’n’ Brew, an underrated two-hander with John Belushi and Jane Curtin’s long-married couple turning each other on by confessing to possibly fictitious extramarital shenanigans and a great short from SNL filmmaker Gary Weiss, pairing street dancers with ballerinas.

Arguably, though, the music stole the show. Steve Martin debuted his silly novelty song “King Tut,” which, with producer Lorne Michaels and the Saturday Night Live band going all-in on a goofily lavish production number, went on to become an unlikely Top 20 single. The episode also kicked off with the introduction of a pet project of cast members John Belushi and Dan Aykroyd: the Blues Brothers.

Bandleader Paul Shaffer, doing a spot-on impersonation of monotone music maven Don Kirschner, starts the show by introducing his latest find, “a new blues act that had been playing in a small, funky club on Chicago’s South Side.” Shaffer proudly proclaims that thanks to his promotion, “they are no longer an authentic blues act, but have managed to become a viable commercial product.” With Belushi introduced as “Joliet” Jake Blues and Akyroyd as his “silent brother Elwood,” Kirschner throws to the very real SNL stage, where the two performers, kitted out in all-black suits, fedoras, and Ray-Ban Wayfarer sunglasses, launch into a creditably energetic cover of Floyd Dixon’s “Hey Bartender,” with Belushi belting out the lyrics and Aykroyd dancing wordlessly alongside before breaking out his harmonica for a raucous solo.

The crowd loved it, even if the stars’ commitment to their alter egos precluded any winking to the camera. Indeed, the Blues Brothers became a musical obsession for both Aykroyd and Belushi, their side project eventually eclipsing Martin’s novelty song by the thousandfold. The pair, in addition to performing their regular cast duties all night, returned for an encore later in the episode, running through an equally enthusiastic rendition of “I Don’t Know,” originally by Willie Mabon and His Combo.

The Blues Brothers' concept coalesced from several different sources. Aykroyd was initially the more well-versed blues aficionado, even occasionally sitting in with local bluesmen Downchild Blues Band in Aykroyd’s native Canada. Belushi, then more into the punk rock and heavy metal scene, quickly latched onto his friend’s blues obsession, their growing enthusiasm fueled by the legendary SNL afterparties at the decrepit New York bar rented by Aykroyd. The jukebox there alternated blues and punk, with an open stage inviting guests to jam into the wee hours.

The first on-air manifestation of the inseparable duo’s blues fixation came back in the show’s second season when, in a goof on the cast-derided Killer Bees running gag, Belushi sang a swaggering version of Slim Harpo’s “I’m a King Bee,” while he, Aykroyd, and “Howard Shore and His All-Bee Band” were dressed in the unwieldy bee suits. After that, the pair would occasionally warm up the SNL audience with some rehearsed blues covers (it was reportedly Shore who came up with the Blues Brothers' name), gradually gathering the confidence to present themselves as an actual blues band on live national TV.

Watch the Blues Brothers Perform 'Soul Man' on 'SNL' in October 1978

It helped that Aykroyd and Belushi assembled a truly exceptional backing band. The Blues Brothers’ horn section included SNL bandmates, Lou Marini and Tom Malone, while Stax session legends guitarist Steve Cropper and bassist Donald “Duck” Dunn had also been the core of Booker T & the MG's. Another guitarist, Matt “Guitar” Murphy, had played with multiple blues greats, while classically trained trumpeter Alan Rubin rounded out the Blues Brothers’ sound. By the time the Blues Brothers hit the Studio 8H stage in April 1978, the backing band was tight, legit and powerful.

As for Belushi, enthusiasm made up for the actor’s unpolished vocals, the spectacle of a famous white comedian fronting a Chicago blues outfit somewhat allayed by the sheer talent surrounding him. Aykroyd’s Elwood eventually shook off his silent schtick, taking the mic to perform numbers such as the band’s cover of novelty doo-wop record “Rubber Biscuit” (originally by '50s New York vocal band the Chips).

Meanwhile, the brothers built up their mystique, with Akyroyd’s eccentric, robotic dance moves colliding with the surprisingly nimble Belushi’s bursts of gymnastic thrashing. Occasionally, Aykroyd would emerge onstage with a briefcase handcuffed to his wrists, only to ceremoniously unlock it and retrieve his trusty harmonica from its depths.

The Blues Brothers, emerging at the height of the early Saturday Night Live’s popularity, were a smash. An album was quickly ordered up, with the all-in Belushi largely finding the subsequent album Briefcase Full of Blues, culled from a triumphant live set opening for Steve Martin at the packed and rowdy Los Angeles Amphitheater. Briefcase Full of Blues went on to sell an astonishing million copies in its first weeks of release, landing at No. 1 on the Billboard chart. A movie deal was immediately struck, with Belushi manager Bernie Brillstein’s pitch cut off by Universal execs with a definitive, “Done!”

For some at Saturday Night Live, Aykroyd and Belushi’s runaway pet project was viewed with not a little bemusement as something of a fluke — a self-indulgent lark that took on a life of its own. Meanwhile, blues professionals scoffed at the idea that Briefcase Full of Blues would become one of the highest-selling blues records ever made. None of that deterred Belushi, who characteristically hurled himself into this newfound source of fame, adulation and cash with abandon. In retrospect, Belushi and Aykroyd (who went on to co-found the House of Blues music venue and restaurant chain) may have been dilettantes, but their sincere respect for the genre managed to shine through, with their championing of sometimes forgotten blues legends at least exposing the SNL stars’ young, mostly white audiences, to the actual music.

Director John Landis’ 1980 Blues Brothers film was a runaway success of musical excess, Aykroyd’s sprawling script and Belushi’s increasing unreliability sending the film’s budget skyrocketing before the film recouped it all, and then some, at the box office. During the writing of the film, Belushi and Aykroyd would depart Saturday Night Live, seeing their inextricably paired career path paved by their musical creations’ massive, multimedia success.

The Band Behind the Blues Brothers

A complete guide to the talented musicians who backed "Joliet" Jake and Elwood Blues.

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