I gave Lennon a few rock tips; Chief feature writer Paddy Shennan talks to the Scouser who played a pivotal role in promoting a machine that revolutionised the music industry.
IT was the world's first workable sampler and, with a little help from The Beatles, it helped revolutionise rock music.
And a central figure in the history of the magical Mellotron, which pre-dated the synthesiser by years, was ... a classically-trained musician from Norris Green.
Geoff Unwin, now 71, worked for the Eric Robinson Organisation, which owned the Mellotronics company, and he became the face - and hands - of the pioneering keyboard in 1962.
He toured the country and appeared on TV shows to demonstrate its capabilities to awestruck musicians and an awestruck public.
Later, The Beatles would give the Mellotron their own priceless seal of approval by using it on the intro to their 1967 hit Strawberry Fields Forever, while Mike Pinder of The Moody Blues, who had worked for Streetly Electronics, which manufactured the keyboard, used it on many songs, including Nights In White Satin.
Geoff even visited John Lennon at his country mansion, Kenwood, in Weybridge, "to give him a few pointers, because musicians were always looking for something new to try".
And now, all these decades on, Geoff and the Mellotron - which has since been used by the likes of OMD, Muse, REM, Radiohead and Oasis and, before them, David Bowie (on Space Oddity, Hunky Dory and Diamond Dogs) and a whole host of 1970s prog rockers, including Genesis and Yes - are very much back in the public eye.
A whole chapter is devoted to Geoff in the new 590-page book Mellotron: The Machine And The Musicians That Revolutionised Rock, by Nick Awde, while members of a New York-based production company which is making a film about the keyboard jetted over to interview him.
"Frankly, I'm amazed that there has been all this interest," says Geoff, who was born in Uldale Close, Norris Green and now lives in Dorset.
The modest musician, who went on to work for EMI in 1969 and wrote the theme tune for the first On The Buses film ("A kind of Knees Up Mother Brown on wheels, it's a load of sh**e, really!") adds: "I'm too embarrassed to read the book!"
Struggling to come to terms with the 21st century interest in a musical phenomenon from the 1960s, and the part he played in it, Geoff explains: "The author of the book kept me on the 'phone for six hours, wanting to know every last detail. Looking back, I had no idea there would be all this fuss all these years on."
But he does admit: "Although I can't believe what's happening, I love it - simply because I think music is a wonderful thing. I am proud of the part I played in the Mellotron's history."
The Mellotron offered musicians any sounds they wanted - its pre-recorded tapes included everything from a symphony orchestra to rock 'n' roll drum rhythms.
Author Nick Awde says: "The Mellotron's trademark otherworldly sound is unmistakable, from the dreamy flutes at the start of The Beatles' Strawberry Fields Forever, the soaring string and choir passages in The Moody Blues' Nights In White Satin, Traffic's Hole In My Shoe and Julie Driscoll and Brian Auger's Wheels On Fire."
But the astronomical expense of the Mellotron ensured that it could never become a mod con for ordinary families. Instead, apart from professional musicians, it attracted the attention of wealthy individuals, like King Hussein of Jordan and gadget-obsessed film star Peter Sellers.
Geoff explains: "A Mellotron cost pounds 1,000, when the average house was pounds 2,000 or pounds 3,000!"
While he is, at times, a little embarrassed to talk about the part he played in the history of the Mellotron, Geoff feels much more comfortable speaking up for his birthplace of Norris Green.
"Personally, I have no book, record or music to plug (I don't even want to plug me!), but I'd like to take the opportunity to throw a little kindly light on old Norris Green," he says.
"I'd like to draw people's attention to the fact that being born in poor circumstances, raised on a council estate and educated in infant and junior classes of up to 42 children did not result in me (and thousands of others) resorting to anti-social and criminal behaviour.
"We all learned how to read and write properly and acquire values of decency which I'm sure still holds true for the silent majority of decent Liverpudlians in Norris Green, who now live in the shadow of a handful of socially inadequate, cocky little twerps who seem to think they can set the agenda for the rest of us.
"It's time people stood up to these little gangsters."
Well said, Geoff.
You should put those uplifting words to music - and I can think of the perfect accompaniment.
Mellotron: The Machine and The Musicians That Revolutionised Rock, by Nick Awde. Published by Desert Hearts (pounds 19.95 in book shops, or from www.desert hearts.com)
DEMO: Geoff Unwin shows off the Mellotron at Harrods; FEELING MELLO: The Beatles used a Mellotron on Strawberry Fields Forever; MODEST: Geoff Unwin