The material explained below is based on the original Derbyshire theme. Subsequent versions of the theme will be covered in the future, and the ways in which they differ will be covered in their individual sections.
Primary Sections
Intro
The Intro section was originally comprised of four repeats of the bassline in the form (E, E, E, G). In the first two, each bassline block is a dum-de-dum, and in the second two, all of the E’s are diddly-dums, with the G being a high-low dum-dum-diddy.
In some later versions, the Intro section is shortened by removing the second half.
Melody 1
All Melody 1 sections begin with a G high-low dum-dum-diddy. The only exceptions to this are when the Melody 1 bassline plays at the end of the bridge or when one Melody 1 leads directly into another.
The bassline during Melody 1 is in the form (E, E, B, B) and always consists of two repeats of:
two E diddly-dums (not dum-de-dums),
a B diddly-dum,
a B low-high dum-dum-diddy.
Melody 2
The bassline during the Melody 2 section is in the form (E, E, G, B, E, E) and always consists of:
two E dum-de-dums,
one G dum-de-dum,
a B low-high dum-dum-diddy,
two E dum-de-dums.
Then follows a segment which is repeated twice, in the form (B, B, B, D) and comprised of:
three B dum-de-dums,
a D high-low dum-dum-diddy.
If leading back into Melody 1, the final D high-low dum-dum-diddy is replaced with a G high-low dum-dum-diddy.
Bridge
As stated above, the bridge bassline always begins with a D high-low dum-dum-diddy. From there, the bassline during the first section of the bridge is in the form (G, G, G, G, D, G, G, G) and consists of:
four low G diddly-dums,
one D dum-de-dum,
three low G diddly-dums.
The second section of the bridge is in the form (C, G, C, G, B, B) and has:
one C diddly-dum,
one low G diddly-dum,
one C diddly-dum,
one low G diddly-dum,
two B diddly-dums.
Note that there is no dum-dum-diddy at the end of the bridge bassline. This is a common misunderstanding, as it is the only place in the theme where two consecutive B bassline blocks are followed by an E without a low-high dum-dum-diddy to link them.
Additional Sections
Bassline Solo
The Bassline Solo consists of two repeats of the first two bars of the bassline of Melody 2 (E, E, G, B).
Ending
The end of the theme consists of two Melody 1 sections back-to-back.
Note that the G high-low dum-dum-diddy that leads into the first Melody 1 is not repeated for the second Melody 1.