52 weeks of blues

“Keep on Knockin'” aka “Keep A’ Knocking” aka “Keep on Knocking (but you can’t come in)” is a jazz/blues/rock standard from the 1920’s. Originally a big band/jazz number, it has spread into just about every genre, with the most well-known version being Little Richard’s 1957 rocker.
John Hurt plays it as an 8 bar, in standard tuning, in the key of A. It is relatively simple in structure from a guitar point of view – a two line verse repeated throughout, with an interlude where only the first two bars are different to the usual progression. However, it’s Mississippi John Hurt, so it’s fast and quite a difficult song to play accurately.
The main features are the alternating bass lines and the incredibly fluid melody. The melody kicks off with a slide into a D lick based on the 5th fret. The slide can be tricky but you always want to play it on the half beat before going into a D chord, as illustrated at the very start of the intro. John improvises a little each time, sometimes playing only off the beat notes, sometimes playing 8th notes to build momentum. The key to getting the fluidity John has here is to realise that his riffs ‘end’ on bar 1 of the next beat – they start half a beat before the bar, and end a beat after the bar. His thumb is playing 1 2 3 4; his fingers aren’t. They deliberately go outside of this and blur the line where one bar ends and the next begins.
Somewhat unusual for alternating bass, John plays a higher string on beats 1 & 3 and alternates with a lower string for beats 2 & 4 in all chords except the E. On the E he alternates in the usual way – low E alternating with 2nd fret D string. The transition between these two seemingly contrasting techniques is fluid because he drops a beat in bar 5 – you keep the same high string/low string pattern with your thumb and the dropped beat means you hit the low E on beat 1 instead of beat 4. The lost beat is picked up again on beat 1 of the next bar. It sounds strange but is quite natural when playing the song.
The combination of this odd timing in the second half of the repetition and John’s beautifully smooth melody lines played over more than 4 beats really separates the bass and melody. It sounds like the melody could be played on a separate instrument. You really want to get the bass down, then just set your thumb to autopilot and concentrate on what you want to do with the melody. There is a fair bit of improvisation on each melody line, but you could realistically play a different lick every time and still have a great sounding tune.

D                                              A
Oh Lord man, you can't come in
A7            E            D               A
Oh Lord man, you can't come in

Keep on Knocking and you can't come in
Keep on Knocking and you can't come in

The interlude

Oh Lord baby are you satisfied?
Tell me baby are you satisfied?

One more time, One more time I'll
One more time I'll be satisfied

Oh Lord man, you can't come in
Oh Lord man, you can't come in

Instrumental verse

Doorbell ringing and you can't come in
Doorbell ringing and you can't come in

The interlude

Oh Lord man, you can't come in
Oh Lord man, you can't come in

A half beat lead in to the progression sets up the song. John alternates the bass behind perfectly fluid melodic lines, attaining masterful separation between the sounds his thumb is making and the sounds his fingers are making.

The beat count in bar 5 is not a typo – he drops a beat in bar 5, playing only 3 beats before hitting the E chord, and picks it up again at the start of bar 7. John improvises over the basic D riff in about half the bars, and plays the ‘standard’ riff in the others – experiment with it and create some nice sounds of your own. In the second repetition he slides up to the 9th fret to set up the interlude.
Verse 1
Verse 2

The interlude slides up to an E7 at the 9th fret, then back to an open D. The bass is really unusual in the D – it sounds like he’s alternating between the open D and the same pitch on the 5th fret A string. I’ve found this impossible to play, so I revert back to the open D and open A of the standard progression. After the interlude he slides straight back into the progression.

John adds a last bar in A with a small chromatically descending turnaround to take us out.