Rock 'n' Roll is just starting to find its feet in the cafes and clubs gaining an audience of insatiable youth ready for something that feels rebellious and freeing.
A good-looking youth who has a few good moves and can sing made over with the latest fashion, haircut and a stage-name and, hey presto, you have a cash-cow.
But where there is a talent to exploit for money there is also rivalry and jealousy.
And so the play starts with the pretty, blond-haired Silver Johnny (Tom Rhys Harries) preparing to perform at the Atlantic Club.
The excitement and energy of the time pounds in the rhythms that come through the floor from the club downstairs.
Fast forward then to later when two staff at the club - Sweets (Rupert Grint) and Potts (Daniel Mays) are anxiously discussing a big meeting going on between the Atlantic's manager Ezra and Sam Ross.
A meeting that could mean big things for Silver Johnny and big money for those who "discovered" him.
As Potts says: "The fish are jumping and the cotton is high".
But this is a black comedy and just as things seem to be looking up for our two and the rest of the club's staff, events conspire against them in a grim and violent way.
Potts and Sweets aren't the brightest sparks and fearing for their lives doesn't help in their thought processes.
To add to their nerves there is Baby (Ben Whishaw) to contend with.
Baby is Ezra's work-shy and psychotic son prone to waving a cutlass in someones face one minute and singing snatches of Rock n' Roll tunes the next.
Skinny (Colin Morgan) is often the focus for Baby's cutlass threats but he seems to be in with Atlantic manager Mickey (Brendan Coyle) for reasons that seem to be more down to hard graft than brain cells.
He looks up to Baby or at least wants to be like him, dressing in the same clothes which add to Baby's dislike.
Mojo is funny but not quite as often as the guffaws of laughter from certain quarters would suggest and it did overshadow the darker moments which give this play its edge.
Something nasty has gone on at the Atlantic and there is humour to be gleaned in how the hapless club workers deal with it but there is also a shading to some of the characters that you have to fight to reach at the moment.
That will change as the production inevitably mellows and evolves.
Rupert Grint impressed on his first professional stage outing.
This isn't quite the Equus character Harry Potter colleague Daniel Radcliffe took on for his debut but he gave an assured performance in a part that was well suited.
Any first-night nerves were well hidden beneath his character's nervous demeanour in the opening scenes - he even looked like he was having fun towards the end.
In fact, the only tell-tale sign that he is a newbie was in the way he looked to the other cast members to take the lead at the curtain call (something I remember Radcliffe doing too).
Colin Morgan's Skinny had a nervous tic and looked gangling and awkward in his own skin, a performance that will no doubt surprise fans of his Merlin character as will Skinny's plot-line - his final scene is very well done. (He also displayed a fine pair of pins).
And as for Ben Whishaw, we hear him before we see him as he demonstrates a fine singing voice and, later, a fine dance move or two.
Baby is the character we learn the most about and for that is the most intriguing.
Ben does unstable and nasty well, and it is great to watch, but it felt that the drama and tension of some of his darker moments were drowned out by over-enthusiastic laughter at the comic lines.
Such was his focus and energy that he broke the cutlass at one point. If I was handing him notes, I'd have liked to have seen him preen a bit more.
Baby strikes me as quite vain and after a while, he stopped fixing his slicked backed sides and quiff with a comb which felt a little out of character. It is early days though.
Brendan Coyle seemed to be channelling the calm strength of Bates for much of his performance but then Mickey is the only person who seems to be able to keep his head while Daniel Mays probably felt like the person who most needed to rein in his energy a little.
He makes a great double act with Colin Morgan's Skinny but his character got a little overbearing at times.
There is a bit of tightening up to do and more to come out of this play but that is what previews are for. The cast did three curtain calls and I'm not quite sure the production deserves it just yet.
Mojo is my most highly anticipated play of the year and it certainly didn't disappoint which is a good thing really because I will be seeing it again.
It runs at the Harold Pinter Theatre until January 25.