George Martin *was* the Beatles
It is a matter of history that George Martin is widely regarded as being the 'fifth Beatle'. He was their producer all the way from the first single through to their final album to be recorded, Abbey Road. Few Beatles songs do not list George Martin as producer.
However, there is strong evidence to suppose that Martin was more than just a producer. In fact, he virtually was The Beatles, and the four mop-headed lads from Liverpool had no higher status than the hired hands that fronted the Monkees.
Let's look at the evidence. Firstly, of the very early material that has emerged, before George Martin's involvement, none achieves the status of anything more than energetically performed rock 'n' roll or cutesy ballad. Yet only a couple of years later 'their' writing was masterful.
None of The Beatles had any musical training. However, the quality of the musical arrangements would stand comparison with the musical greats of any century. Take for example I Am The Walrus, credited to Lennon and McCartney but widely acknowledged to be Lennon's work. The introduction - just the introduction mind - has a sequence of eight complex chords that could only be the work of someone who has studied harmony deeply and has the wealth of background and experience to derive such a sequence. And who has that musical knowledge? George Martin of course who studied at the Guildhall School of Music. Martin has publicly proven himself to be a very capable composer.
Now, take the arrangement for Penny Lane, ostensibly one of McCartney's songs. During this short song, the key changes - or modulates - no fewer than seven times. This would be a feat for a highly competent classically trained composer to accomplish (in a movement from a symphony, typically the key modulates once, then modulates back again, that's all). It would be impossible for a 24-year old McCartney to do this seven times in one song. George Martin could do it though - and in fact he has done it incredibly well because at no point does the listener become aware of any musical 'trickery' going on.
My third demonstration is Eleanor Rigby. It is no secret that the string arrangement is the work of George Martin. But the song itself betrays touches of which Schubert would have been proud. And of course Schubert would have been part of Martin's musical education.
The Beatles are widely regarded as studio innovators too. However, George Martin had already built up a significant reputation as a producer of comedy recordings before the advent of The Beatles. There is little in terms of creativity that Martin would not have been capable of, assisted by highly competent Abbey Road engineers.
The final proof is the one complete album that George Martin did not produce - Let It Be. By this time, some of Martin's skills had rubbed off and most of the songs are workmanlike or even quite good (and some are dreadful). But compared to Revolver, Sgt. Pepper or Abbey Road? There's no comparison.
I think it's time that The Beatles, well McCartney at least, come clean and give George Martin the credit he is due as the most successful popular songwriter and composer ever. The 'fifth Beatle'? George Martin was The Beatles!