Indeed this is a question that has been argued over for decades by historians, musicologists and even civilians. Why, there's even a Wikipedia page that tries to answer the question (but only leads to muddy waters). The answer is simple but before we get there we just need to mention a couple of pretenders to the throne.
One commonly proposed contender is Rocket 88. It's a valid suggestion. The record has fuzzed up guitars, a dirty saxophone and lyrics about riding around in my Rocket 88.
Credited to singer Jackie Brenston and his Delta Cats, it was recorded at Sam Phillips' Memphis Studio in March 1951. The band was Ike Turner's Kings of Rhythm, with sax player Brenston taking the vocal lead, Ike playing piano and Willie Kizart on guitar.
Rocket 88, Jackie Brenston and Delta Cat, 1951
One person that thought Rocket 88 was rock n roll was Sam Phillips - and, well, his opinion counts. But one vote against comes from Ike Turner who said:
They say "Rocket 88" was the first rock'n'roll song, but the truth of the matter is, I don't think that "Rocket 88" is rock'n'roll. I think that "Rocket 88" is R&B, but I think "Rocket 88" is the cause of rock and roll existing.In the 1950s black music was heading towards rock and roll: the blues had got rhythm, jazz had got modern (though sometimes it got played too darn fast and changed the beauty of the melody until it sounded just like a symphony) but there was something missing.
Hank Williams' Move It On Over (1947) would fit right in to any rock n roll band's repertoire. Any rock n roll band. Or any country, swing, country swing, Western swing, country & western, hillbilly, rockabilly or skiffle band. But it's not rock n roll.
Move it on over, Hank Williams, 1947
guard of honour, Hamble River wedding party, 2012
Imagine some kind of wedding guard of honour, two lines of people holding flags or banners. The flags of the first two have the words Folk and Blues, the next pair Country and R&B, behind them Jazz and Sinatra, then Gospel and Church music, in the background Doowop and Barbershop. The flags go on further than the eye can see, with ever more esoteric coming-togethers. And walking down the aisle, bringing all the flags together is Elvis, gathering them, simultaneously tying them and shredding them.
Everyone knows the story of Elvis: how 60 years ago, on July 5th 1954, a small spacecraft crash landed just outside Memphis and Elvis, Scotty and Bill climbed out. They found their way to Sam Phillips studio where they thought they could use his recording equipment to record a message to be played on the radio and sent back to the stars from whence they came. The message was recorded, it was played on the radio and the shot was eventually heard around the world. And that message became known as The First Rock n Roll Song. That's alright.
That's Alright Mama, Elvis, Scotty and Bill, 1954