While the pair drove through the streets of McCartney's hometown of Liverpool, they belted out beloved Beatles songs before the segment got unprecedentedly deep and emotional.
"Your music is so full of positivity and joy and a message of love and togetherness," Corden told the celebrated singer. "I feel like it's more relevant now today than it's ever been."
"That’s one of the strangest things, is we expected it to last 10 years, but it keeps going on and on and on," McCartney said of The Beatles' enduring fame and adoration. "And it keeps being relevant."
The singer then went on to share a bit of background on the origins of one of their most uplifting songs, "Let It Be," off the band's final studio album in 1970.
Paul McCartney in the 1960s
Paul McCartney in the 1960s
Filed 1963-London, England: Head and shoulders of Beatles' bassist Paul McCartney. He is wearing a tweed jacket and a tie.
LONDON - 30th DECEMBER: Paul McCartney and John Lennon (1940-1980) from The Beatles posed backstage at the Finsbury Park Astoria, London during the band's Christmas Show residency on 30th December 1963. (Photo by Val Wilmer/Redferns)
The Beatles in 1965. The Beatles - John Lennon (1940-1980), Paul McCartney (born 1942) George Harrison (born 1943) and Ringo Starr (born Richard Starkey, 1940) - were one of the most creative and successful rock groups of the century. The Beatles formed in 1961 and disbanded in 1970 after a string of hit songs and critically acclaimed albums. (Photo by Hulton-Deutsch/Hulton-Deutsch Collection/Corbis via Getty Images)
LIVERPOOL - CIRCA 1962: Rock and roll band 'The Beatles' pose for a portrait in circa 1962. (L-R) Paul McCartney, John Lennon, George Harrison, Ringo Starr. (Photo by Michael Ochs Archives/Getty Images)
The Beatles, early group portrait, (L-R) Ringo Starr, Paul McCartney, John Lennon, George Harrison - posed, backstage, 1962. (Photo by Harry Hammond/V&A Images/Getty Images)
HAMBURG, GERMANY - 1st MAY: The Beatles posed in Hamburg, Germany during their residency at The Star Club in May 1962. Left to right: Pete Best, John Lennon (1940-1980), Paul McCartney and George Harrison (1943-2001). (Photo by Horst Fascher/K & K Ulf Kruger OHG/Redferns)
UNSPECIFIED - CIRCA 2000: Photo of BEATLES; Ringo Starr, John Lennon, George Harrison, Paul McCartney - receiving Variety Club 'Show Business Personalities of 1963' awards (Photo by John Rodgers/Redferns)
UNITED KINGDOM - DECEMBER 15: THANK YOUR LUCKY STARS Photo of Paul McCARTNEY and BEATLES, of The Beatles, performing at Alpha Television Studios, Aston, Birmingham (Photo by David Redfern/Redferns)
The Beatles sign autographs for a young fan after concert at the Odeon in Southend-on-Sea, Autumn 1963 UK Tour, 9th December 1963. George Harrison, Ringo Starr, John Lennon, Paul McCartney. (Photo by Daily Mirror/Mirrorpix/Mirrorpix via Getty Images)
26th October 1965: British pop group The Beatles, from left to right; Ringo Starr, John Lennon (1940 - 1980), Paul McCartney and George Harrison (1943 - 2001), outside Buckingham Palace, London, after receiving their MBE's (Member of the Order of the British Empire) from the Queen. (Photo by Fox Photos/Getty Images)
(Original Caption) Portland, Ore.: John Lennon (right) smiles as Paul McCartney speaks at press conference held after Beatles performance in Portland.
OBERTAUERN AUSTRIA - MARCH 1965: Paul McCartney of the rock and roll band 'The Beatles' poses for a photo in the snow in March 1965 in Obertauern, Austria during a break from filming their second movie HELP!. (Photo by Michael Ochs Archive/Getty Images)
Beatles singer and songwriter Paul McCartney wearing a straw hat while filming 'Help' in The Bahamas, 2nd March 1965. (Photo by William Lovelace/Express/Getty Images)
Members of the British rock band The Beatles, Paul McCartney (left) and John Lennon (1940 - 1980), sing into a microphone as they play their instruments at the taping of a segment for 'Toast of the Town,' the CBS variety program hosted by Ed Sullivan, New York, August 14, 1965. The segment aired as part of Sullivan's 19th season opener on September 12, 1965. (Photo by CBS Photo Archive/Getty Images)
UNITED KINGDOM - SEPTEMBER 12: Photo of MAGICAL MYSTERY TOUR and Paul McCARTNEY and BEATLES; Paul McCartney next to the Magical Mystery Tour coach (Photo by David Redfern/Redferns)
UNITED KINGDOM : Caption reads: 'Why has Beatle Paul got his eyes shut? - he's meditating'. Paul McCartney (1942-) formed the Beatles in 1960 with John Lennon (1940-1980), George Harrison (1943-2001) and Ringo Starr (1940-) in Liverpool, England. They went on to become the most successful pop group of all time and finally split in 1970. Paul McCartney subsequently went on to form Wings with his wife Linda, as well as having a successful solo career. McCartney was awarded a knighthood in 1997. (Photo by SSPL/Getty Images)
Paul McCartney and girlfriend Jane Asher. June 1968 Y5673-008 (Photo by Daily Mirror/Mirrorpix/Mirrorpix via Getty Images)
English musician, singer, songwriter, and composer Paul McCartney records the Lennon-McCartney composition 'Thingumybob' with the Black Dyke Mills Band in Saltaire, City of Bradford, West Yorkshire, 30th June 1968. (Photo by Tony Evans/Timelapse Library Ltd./Getty Images)
English musician, singer, and songwriter Paul McCartney marries American musician and photographer Linda Eastman (1941 - 1998) at Marylebone Registery Office, London, 12th March 1969. (Photo by C. Maher/Daily Express/Hulton Archive/Getty Images)
UNITED KINGDOM - SEPTEMBER 25: Photo of Paul McCARTNEY and BEATLES; Paul McCartney at the opening of 'Midnight Cowboy (Photo by Andrew Maclear/Redferns)
UNITED KINGDOM - MARCH 12: Wedding of Paul McCartney with American photographer Linda Eastman at the Marylebone register office on March 12, 1969 in London, United Kingdom. (Photo by Keystone-France/Gamma-Rapho via Getty Images)
UNITED KINGDOM - JANUARY 01: Photo of Paul McCARTNEY and BEATLES; Portrait of Paul McCartney, circa 1968 / 1969 (Photo by David Redfern/Redferns)
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"I had a dream in the '60s where my mom, who died, came to me in the dream and was reassuring me, saying, 'it's gonna be OK. Just let it be.'" McCartney recalled. "She gave me the positive word. So I woke up and I went 'What was that? What'd she say? Let it be? I've never heard that. That's kinda good.'"
"So I wrote the song 'Let it Be,' [and it was] about positivity," he added.
"That's the most beautiful story I've ever heard," Corden said before the two broke out in an emotional duet of "Let it Be" that brought tears to talk show host's eyes as he drove.
"Oh man, it got me emotional there," Corden said, wiping his eyes after the song. "I didn't feel it coming."
Explaining why the moment got him so choked up, Corden said, "I can remember my granddad, who was a musician, and my dad, sitting me down and saying, 'We're going to play you the best song you've ever heard. And I remember them playing me that."
"If my granddad were here right now, he'd get an absolute kick out of this," Corden added, with tears still in his eyes.
McCartney made the emotional moment even more poignant when he reassuringly told Corden, "He is."
From Penny Lane to the singer's childhood apartment where Lennon and McCartney wrote some of their most iconic songs, the pair brought viewers on an enlightening and nostalgic journey through the band's iconic history -- bringing excited shock and joy to the random people Corden and McCartney met throughout the excursion.
The joyous "Carpool Karaoke" concluded at a local pub, the Philharmonic Dining Rooms, where The Beatles used to play when they were just starting out.
Setting up hidden cameras around the bar, Corden gave the regular pub-goers a surprise they’d never forget. Posing as a regular bartender, Corden served a drink or two before asking a patron to select a song on the jukebox.
After unsuspectingly picking a Beatles song and returning to her table, the bargoer -- and everyone else in the place -- was shocked when large heavy curtains around the pub's stage suddenly opened revaling McCartney and a full band, who broke out in a performance of "A Hard Day's Night."
The unexpected concert continued as the music legend rocked out with a slew of beloved hits, while many of the patrons were moved to tears by the surprise.
The Beatles perform in Liverpool's Cavern Club, with Pete Best on drums, 1962. Best was fired from the group that same year, and replaced with Ringo Starr. (Photo by Mark and Colleen Hayward/Getty Images)
1963: Rock and roll band 'The Beatles' pose for a portrait in 1963. (Photo by Michael Ochs Archives/Getty Images)
NEW YORK - FEBRUARY 7: The Beatles arrive at John F. Kennedy International Airport, February 7, 1964. At top is Ringo Starr, middle row is John Lennon and Paul McCartney, lower level is George Harrison and unidentified flight attendant. (Photo by CBS via Getty Images)
NEW YORK - FEBRUARY 9: The Beatles prepare for their first appearance on The Ed Sullivan Show in New York, February 9, 1964. From left to right, Paul McCartney, Ringo Starr (in background, on drums), George Harrison, John Lennon. (Photo by CBS via Getty Images)
UNITED STATES - AUGUST 16: The Beatles at Shea Stadium. Our Mets have displayed their antic behavior before some good crowds at Shea Stadium but last night's turnaway mob of shrieking teeners tested the solidity of the ballpark as they flocked to see Britain's moptop quartet in concert. Scores were injured in the crush or overcome by the humid heat but luckily no one required hospitalization. (Photo by Dan Farrell/NY Daily News Archive via Getty Images)
UNITED KINGDOM - SEPTEMBER 12: PLYMOUTH HOE Photo of MAGICAL MYSTERY TOUR and BEATLES, L-R: John Lennon, Paul McCartney, George Harrison, Ringo Starr - posed, group shot - during Magical Mystery Tour. (Photo by David Redfern/Redferns)
24th June 1967: British pop group The Beatles holding banners proclaiming 'All You Need Is Love' in four languages, in preparation for a global television performance of their song of the same name. (Photo by Doug McKenzie/Getty Images)
UNITED KINGDOM - JANUARY 01: Paul MAC CARTNEY, George HARRISON, Ringo STARR and in front John LENNON interpreting the song I'M THE WALRUS disguised as animals, in a scene from the film MAGICAL MYSTERY TOUR. (Photo by Keystone-France/Gamma-Keystone via Getty Images)
British musican and artist John Lennon (1940 - 1980) holds Japanese-born artist and musician Yoko Ono in his arms, December 1968. (Photo by Susan Wood/Getty Images)
The four members of the British group the BEATLES posing together on August 2, 1967. At that time they stopped their concerts, wore the moustache and announced their separation despite their last album to come, ABBEY ROAD in 1970. (Photo by Keystone-France/Gamma-Keystone via Getty Images)
Photo of BEATLES; George Harrison, Ringo Starr, John lennon & Paul McCartney with actress Jane Asher, Maureen Starkey and Pattie Boyd at a party to celebrate the musician's 25th birthday at Rishikesh, India, 25th February 1968. (Photo by Cummings Archives/Redferns)
Staff Photo by Jill Brady, Wednesday, August 9, 2006: Beatles Abbey Road record album. (Photo by Jill Brady/Portland Press Herald via Getty Images)