This document responds to other discussions on this topic which would have us believe that the undoubtedly distinctive and instantly recognisable sound was some kind of sonic accident arising from a complex interaction of disparate sounds produced on undetermined instruments played in unorthodox ways. Moreover, there is an assertion that a scientific approach using computer driven mathematical algorithms is the surest method to unravel the great mystery once and for all.

Topics discussed below are:
The A Hard Day's Night Chord - Rock's Holy Grail - the best summation outside this site
Mathematics, Physics and A Hard Day's Night - Dr. Jason Brown's celebrated travesty
G7sus4 - the tribute band's choice
Fadd9/G - the Gary Moore variant
Gm7add11 - the original transcription from 1964
Drop the guitar against the amp - not entirely a joke
Randy Bachman's visit to Abbey Road Studios with Giles Martin - (in)directly from the isolated multitracks

link to: The A Hard Day's Night Chord - Rock's Holy Grail

This widely quoted source summarises the findings of others - some of which is dubious and/or spurious. The conclusion falters in the specifics.
The article describes where a "tone intertwines with" the 12-string and produces "strange oscillating effects" interacting with the acoustic guitar - all as a result of some "very clever" bass part.

  • "McCartney could have played a 'low D' ... but this would have provided a quite 'booming' tone. Instead, McCartney opted to play a 'high D' at the 12th fret of the D string."
    Paul does play the low D. It is not a "booming tone" here or in the remainder of the song. He generally avoided playing notes high up the neck on the Hofner as the intonation was poor at that time.
  • "The effect of the F from Lennon's guitar dropping off in favour of McCartney's D note is attributed to the sound of McCartney's bass resonating in the soundbox of Lennon's acoustic and being captured up by his pick-up."
    The increasing dominance of the Bass over the duration is a result of compression. The Acoustic Guitar is an overdub on a separate track and its soundbox could not have been resonating with Paul's Bass.
  • "when Harrison struck that mighty chord on 16th April, 1964, he was playing the top four pairs of strings of his guitar"
    The Fadd9 voicings utilise all six strings/pairs not just the top four.


link to: Mathematics, Physics and A Hard Day's Night

This widely published and celebrated document examines (rather ineptly) the results of the fourier transform, ignores most of the empirical evidence available and inevitably makes several wrong conclusions.
The "Musical Forensics" process identifies nearly 30,000 frequencies and then selects a handful of the loudest and presumes those to be notes played on instruments.

  • The lowest notes identified as being played are A2 and D3.
    Yet we can hear D2 in the Bass, D2 and G2 in the Piano and F2 in the Guitars.
  • The analysis finds just three F-notes (all F3's) and attributes them to the fact that "Pianos have three strings for every note". The document claims that any F-notes could not have come from George's guitar, while Lennon's guitar provides just a single C-note.
    Empirical evidence shows two guitars contributing six F-notes as fundamentals, thirteen more F's would appear as harmonics in the examined range - given a sample with a more appropriate amplitude threshold.
  • "The frequencies of the three F3's were slightly different, but each string on a piano is individually tuned and is likely to be slightly off from one another in the triple."
    That would be a badly tuned piano. Far more likely is the wobbly tuning of the 6th-strings of the two guitars being fretted at Fret-1 by the thumb over the top of the neck. Those three strings add two F3-harmonics and one F3-fundamental.
  • "George Martin played D3 F3 D5 G5 E6 on the piano. ...one extra E6...is taken as a harmonic."
    Aside from this being a clumsy fingering the piano part on the recording sounds nothing like this pretty voicing - it is a low growl. There are several E-notes present but none are being played - they are all harmonics.
The presumption that louder frequencies are played notes is wrong.
Here is an example of spectrum analysis provided by Andy Robinson's excellent Transcribe! software. The program performs the same fourier transform, the frequency-to-note conversion and illustrates the relative amplitudes graphically.
Thus "Musical Forensics" shows an E dominant seventh chord - E7

E2 Spectrum

That's E2 - the first note of "Day Tripper" and its frequency doesn't appear at all!

Read more detail on how Dr Brown got it wrong.



The tribute band's choice actually sounds most like the chord as heard on the recording.
Because of the piano...
  • The piano plays Gsus4 and was recorded with significant low-cut EQ. The notes G2, D3, G3 and C4 from that chord are duplicated in this voicing of G7sus4 when played on a 12-string guitar and the trebly sound of an electric 12-string effectively mimics the rich harmonics of a piano.



Quoted as the chord George Harrison had shown to Gary Moore this includes the important low G-note from the piano part.

  • Bearing in mind that the interview containing Gary's recollection is subject to transcription and editing the probable sequence is that George played Fadd9, Gary offered his own chord (likely G7sus4) and then they devised a fingering to include the low-G.
  • Could possibly arise from a misinterpretation of George's phrase "a G on top". Many guitarists refer to the top and bottom strings of their instrument in non-musical terms which contradict the real meaning i.e. the top string is the one furthest from the floor rather than the one with the highest pitch.


This includes a Bb-note which is clearly not in the recording.
  • Some proponents are merely incorrectly identifying G7sus4. Indeed, the fingering has been described as "play Gm7 barre chord at the third fret and then add the C-note at Fret-5 on the third string" - which unwittingly replaces the Bb-note and the chord is no longer minor.
  • The original sheet music is transposed to the key of C. Gm7add11 is correct in that key and the chord can be played by barring all strings at Fret-3.
Which leads us to...

Drop the guitar against the amp

Not too surprisingly this sounds authentic since the open strings produce Em7add11 which is the right notes transposed a whole step higher. Many 12-string instruments are routinely tuned a half or whole step down to reduce tension in the neck but that was not the case for George's guitar at this time.

Randy Bachman's visit to Abbey Road Studios with Giles Martin

This one purports to be beyond criticism given Randy's assertion that he was shown the individual tracks separately. So he heard the instruments, recognised the notes, and comitted the whole thing to memory...

Unfortunately there are several obvious misquotes of Randy's description (including a C in the Bass!!) so this response will focus on the recorded demonstration:
link to: Randy Bachman's Guitarology 101 on CBC

  • Paul's Bass - Hmm... seems Randy is unsure what the bass note was. He confirms D and significantly makes no allusion to it being any special D played high up the neck.
  • John's Rhythm Guitar - Dsus4 is such a distinctive recognisable sound on a guitar it's difficult to accept that an experienced guitarist would identify Lennon's part as that chord. Surely there would have been a guitar handy in Abbey Road Studios to play along and compare...

  • George - Randy describes George's Fadd9 as having a both a low-G and a low-C.


    Now this is difficult enough to finger on any guitar let alone trying to produce a clean tone while pressing on four strings with the thumb over the extra wide neck of a 12-string. Indeed, Randy's slow strum mutes the 3rd-string (losing two important A-notes) and the two shots with the band omit the low-C.

Even without access to multitracks the left-channel of the stereo mix isolates the 12-string from the Piano and there is no low-G evident. Conversely, the famous A Hard Day's Night Chord is still recognisable in the right-channel when we take out the 12-string Guitar and the Bass leaving just an Acoustic Guitar and a Piano. Fadd9/D with a low-G is the sound. The energy and body comes from the Piano. What's missing from there is the high-F and high-A provided by the 12-string which creates the chiming cluster of F-G-A.

Sure enough, the Bachman Band's rendition sounds fairly authentic because most of the relevant notes are present. However, without the Piano and significant low-cut EQ, it is simply another cover-band compromise reproduction of the ensemble.