Q2 Realising a Figured Bass

“Realising a figured bass line” is a type of harmony exercise, where the figured bass is used to construct both a melody and inner harmony parts.

A question will look something like this. You need to write in the soprano, alto and tenor parts.

ABRSM Grade 6 Music Theory Q2 Realising a Figured Bass

To be successful at this question, you need to keep in mind everything you have learned about harmony so far, including the guidelines about:

  • Doubling
  • Omissions
  • Spacing
  • Voice leading
  • Consecutives
  • Range
DoublingNever double the leading note. Double the 3rd in diminished triads. Double the 5th in 6/4 chords. Avoid doubling the 3rd in major root position chords.
OmissionsNever omit the root or 3rd. Use a complete triad for diminished chords.
SpacingKeep the top three parts close (maximum 1 octave between each part). The tenor should be widely spaced from the bass, unless the bass is high.
Voice leadingSoprano part should be musical (not too repetitive or angular). Tenor and alto should move as little as possible. Leading note usually rises by a semitone to tonic where possible. Avoid all melodic augmented intervals. Resolve all melodic diminished intervals.
ConsecutivesAvoid all consecutive perfect 5ths and octaves.
RangeLimit to high G soprano, down to low F bass. Tenor may rise to G above middle C.

You will also be marked on notation, including correct rhythmic notation, beaming and stem direction, correctly placed accidentals, and so on.

There are many possible strategies for completing a realisation question. You may like to experiment to find the method that suits you best. Some ways to try are:

  • Start with the complete soprano line, then add the alto and tenor. (The advantage of this method is that you can focus on creating a successful melody line).
  • Start at the end (SAT) and work backwards. (The advantage of this method is that by beginning with the cadences, you can work logically using the rules of voice leading).
  • Start at the beginning and work through one complete chord at a time. (The advantage here is that you are less likely to run into problem areas, but may end up with a less interesting tune).

Whichever method you choose, the chances are you will need to rub something out or even start again from scratch at some point, so find a soft pencil and sketch your ideas in lightly until you have finished the whole exercise.

Here is one possible solution to the above question:

Grade 6 ABRSM music theory Q2 realisation model answer

Here are some tips:

  • Find and write down the leading note before you start, so that you remember to check its voice leading (it rises to tonic) and doubling.
  • Find any diminished chords (vii°, and also ii° in minor keys) before you start, so that you remember to use the correct doubling.
  • Find any 6/4 chords and make a memo for doubling.
  • Avoid using the dominant as the first note in the soprano. (This is because it belongs to both chord I and V, and you can easily get “stuck” on the same note. This is not a problem in the alto or tenor).
  • End on the tonic in the soprano part if possible.
  • Aim for the soprano and bass to move in contrary motion where possible, and always when both parts leap (3rd or more).
  • Check for consecutives with every note you write! Don’t leave it until the end, it will be too late.
  • Keep the upper three parts as close together as you can without breaking any other rules.
  • Often one error has a knock-on effect of causing problems. If you are stuck, check for earlier errors.