In question 2 of the grade 7 exam, the most common type of question asks you to add melodic decoration to a Bach chorale. (Another type of questions is the “keyboard reconstruction” which is covered in a later lesson).
You are given the basic chords, (called a “harmonic outline”), on stave A, and on stave B below, you need to copy over the chorale and add appropriate decoration. The question will be about 8 bars long. The first bar or so will be done already, plus a few other notes here and there.
Chorales were vocal hymns. They consist of short phrases which are often only a couple of bars long. Each phrase ends with a paused cadence, which might be on a minim (half note) or crotchet (quarter note). A complete chorale is only about 12 bars long.
The question is worth 15 points, so you should normally add around 12-13 individual decorations, and more than that is also possible. If you add fewer than that, you are unlikely to score full marks, even if what you added was very good.
To score well in this question, you need to make sure that you obey the rules of harmony which were commonplace in the 18th century:
- No consecutive 5ths or octaves (either between adjacent chords, or adjacent notes). Sometimes the harmonic outline includes consecutives, so you will need to find a way to eliminate them.
- No melodic augmented 2nds (this mistake happens in minor keys).
- Use mostly unaccented passing notes (around 90%), plus one or two other appropriate types of decoration.
- Include suspensions if you are able.
- Do not aim to include retardations, anticipations or changing notes. They are not often used in chorales.
Unaccented passing notes and suspensions will often supply you with enough material to write a complete answer, but sometimes you might need to add something else, either because you have not added very much to the chorale overall, or because the momentum of the music keeps stopping.
In these situations, the best type of decoration to add is usually either accented passing note, or auxiliary harmony notes. Standard auxiliary notes are normally only used when decoration is placed in two or more parts at the same time.
Momentum
Most chorales move constantly at the speed of a quaver (8th note). Only occasionally do we find undecorated longer notes. However, the paused note at the end of a phrase should never be decorated.
You should aim to decorate most of the beats, but don’t worry if one beat in a bar here or there cannot be decorated.
Semiquavers (16th notes), appear from time to time, but never in a large numbers.