On the Subject of Chord Progressions

Who knew this bomb's manufacturer would be so into music theory.

  1. A chord will be displayed on the screen near the bottom of the module. Use the following instructions to determine what key the chord is in.
  2. Using the table below, identify the Roman numeral of the displayed chord within the specific key.
  3. Use the progression chart to then find where the chord is in the key's progression, and determine which chord should come next. Note that the curved arrow following the I leads back to the beginning of the chart.
  4. Find the chord's type by once again using the table below, and input that chord type into the module using the buttons above and below the two square screens in the middle.
  5. Press the submit button to submit your answer.

Determining the Key

  • If the first letter of the serial number is between A and G, then the key is D.
  • Otherwise, if the bomb has an unlit SIG indicator, then they key is E♭.
  • Otherwise, if the bomb has a lit IND indicator, then the key is F.
  • Otherwise, if the bomb has an RJ-45 port, then the key is G.
  • Otherwise, if there are more than two AA batteries on the bomb, then the key is A.
  • Otherwise, if there are two or more of the same type of port on the bomb, then the key is B♭.
  • Otherwise, the key is C.
Table of Chords
C Major D Major E♭ Major
I C E G CM I D F♯ A DM I E♭ G B♭ E♭M
ii D F A Dm ii E G B Em ii F A♭ C Fm
iii E G B Em iii F♯ A C♯ F♯m iii G B♭ D Gm
IV F A C FM IV G B D GM IV A♭ C E♭ A♭M
V G B D GM V A C♯ E AM V B♭ D F B♭M
vi A C E Am vi B D F♯ Bm vi C E♭ G Cm
vii° B D F vii° C♯ E G C♯° vii° D F A♭
F Major G Major A Major
I F A C FM I G B D GM I A C♯ E AM
ii G B♭ D Gm ii A C E Am ii B D F♯ Bm
iii A C E Am iii B D F♯ Bm iii C♯ E G♯ C♯m
IV B♭ D F B♭M IV C E G CM IV D F♯ A DM
V C E G CM V D F♯ A DM V E G♯ B EM
vi D F A Dm vi E G B Em vi F♯ A C♯ F♯m
vii° E G B♭ vii° F♯ A C F♯° vii° G♯ B D G♯°
B♭ Major
I B♭ D F B♭M
ii C E♭ G Cm
iii D F A Dm
IV E♭ G B♭ E♭M
V F A C FM
vi G B♭ D Gm
vii° A C E♭

Progression Chart

NOTE: If there are two options for which chord should come next in the progression, and the sum of the numbers in the serial number is greater than or equal to 9, then the chord on the top should be used as the next chord in the progression. Otherwise, if the sum of the numbers in the serial number is less than 9, then the chord on the bottom should be used as the next chord in the progression.

Appendix CP1: Musical Symbol Identification Reference

Musical symbols may be found on the three screens within the Chord Progressions module.

Note Identification Symbols

Symbol Meaning
Sharp
Flat
Natural

If a note does not have a symbol next to it, then the note is natural.

Chord Identification Symbols

Symbol Meaning
M Major
m Minor
° Diminished