‘Ground bass’ compositions have a bass line that repeats throughout the piece, usually exactly. Many musicians have found this a compelling compositional constraints for keeping them … well … grounded!

These files help you explore some of the ways to create effective ground bass compositions, creating variety through re-harmonising the same bass in different ways, and varying the texture.

Specifically, this repo offers:

  1. A ‘cheat sheet’ for re-harmonising any bass interval in .mscz or .pdf formats.
  2. Template scores with only the ground bass provided (a simple version of cut outs)
  3. Analysed, annotated files with Roman Numerals and more.

Below are links to - and further explanation of - those files. First, here’s a preview / embed of the ‘cheat sheet’

Downloads

  Annotation Template Score
Bach Crucifixus B Minor mass BWV232 .mscz, .mxl .mscz, .mxl
Corelli La Folia Coming soon .mscz, .mxl
Purcell Chacony in G Minor Z730 Highlights (.mscz), Highlights (.mxl) Full (.mscz), Full (.mxl) .mscz, .mxl
Purcell Here the deities approve Coming soon .mscz, .mxl
Purcell Sonata in G Minor Z807 .mscz, .mxl .mscz, .mxl

1. Multiple Harmonisations of a Given Bass

.mscz, .pdf

This ‘cheat sheet’ shows how you can harmonise any bass interval in several different ways. It is organised by bass interval: both ascending and descending forms of each interval from minor seconds to tritones. This is supposed to help you work out your options - you definitely don’t need to use all of these!

Check out how the analysed pieces make judicious use of a few of those options, and especially where they avoid the main perfect cadences at the start/end of each ground iteration, just once or twice joining them together with a subtler seam.

2. Composition Exercises

These template scores allow you to try your hand at composing music based on some great ground basses from the repertoire.

Take a template and try to compose:

  • a simple, diatonic harmonisation of the ground in blocks chords as a prototype, making sure to follow good voice-leading practice;
  • a set of alternative harmonisations including tonicisations of other keys and re-harmonising the first note in particular to vary the apparent phrase length (let the cheat sheet help in this);
  • melodic parts that fit with the bass and create more interesting textures. Imitative upper parts can be particularly idiomatic;

Finally, combine the best of your ideas into an overall piece that balances textural and harmonic interest and charts an overall trajectory.

3. Purcell’s Sonata

This section takes the example of Purcell’s Sonata, summarising the imitation and tonicisations.

The melodic imitations are labelled ‘D’ and ‘C’ on the score, and in the table below. This is short for ‘Dux’ and ‘Comes’ – ‘leader’ and ‘follower’. Note the double imitation starting in m.196 and imitative (with parts swapped) in m.201.

D. Part D. Measure D. Beat D. Pitch C. Part C. Measure C. Beat C. Pitch Beat gap Pitch interval
1 1 1.0 D5 2 3 1.0 G4 6.0 P5
1 6 1.0 G5 2 7 1.0 D5 3.0 P4
2 10 3.0 D5 1 11 3.0 D5 3.0 P1
1 20 2.0 D5 2 21 2.0 G4 3.0 P5
2 27 2.0 C5 1 29 2.0 D5 6.0 M2
2 30 2.0 D5 1 31 2.0 D5 3.0 P1
2 33 1.0 D5 1 34 1.0 C5 3.0 M2
2 36 1.0 G4 1 36 2.0 G4 1.0 P1
2 41 2.0 E-5 1 41 3.0 B-5 1.0 P5
2 46 1.0 D5 1 47 1.0 E-5 3.0 m2
2 51 1.5 G5 1 52 1.5 D5 3.0 P4
2 56 1.0 E-4 1 56 2.0 C5 1.0 M6
1 61 2.0 G4 2 62 2.0 D5 3.0 P5
1 63 1.0 G5 2 63 2.0 C5 1.0 P5
2 66 1.5 G5 1 67 1.5 D5 3.0 P4
2 71 2.0 D5 1 71 3.0 G5 1.0 P4
1 81 1.25 G5 2 82 1.25 D5 3.0 P4
1 91 1.0 B-4 2 94 1.0 D4 9.0 m6
1 95 2.0 A4 2 97 2.0 D5 6.0 P4
1 99 1.0 D5 2 102 1.0 D5 9.0 P1
1 106 1.0 E5 2 108 1.0 B-4 6.0 A4
2 111 2.0 D5 1 112 2.0 A4 3.0 P4
2 117 2.0 D5 1 118 2.0 A5 3.0 P5
2 121 1.0 G4 1 121 3.0 D5 2.0 P5
1 129 2.0 D5 2 130 2.0 A4 3.0 P4
1 133 1.5 D5 2 133 2.5 G4 1.0 P5
2 136 1.0 G4 1 137 1.0 D5 3.0 P5
2 141 1.0 G4 1 142 1.0 D5 3.0 P5
2 146 1.0 G4 1 147 1.0 D4 3.0 P4
1 151 1.0 G4 2 153 1.0 G4 6.0 P1
1 156 2.0 E-5 2 157 2.0 A-4 3.0 P5
1 161 2.0 E-5 2 162 2.0 A-4 3.0 P5
1 166 1.0 G4 2 167 1.0 D4 3.0 P4
1 171 1.0 G4 2 171 2.0 G4 1.0 P1
2 176 1.0 G5 1 177 1.0 D5 3.0 P4
2 178 1.0 E-5 1 178 2.0 E-5 1.0 P1
1 181 1.0 G5 2 181 2.0 G5 1.0 P1
1 182 1.0 D5 2 182 2.0 D5 1.0 P1
1 186 2.0 D5 2 187 2.0 A4 3.0 P4
2 196 1.0 G4 1 201 1.0 B-4 15.0 m3
1 196 1.5 G5 2 201 1.5 D5 15.0 P5
1 206 1.0 B-4 2 208 1.0 B-4 6.0 P1

And some other information.

Notes Measure Beat
Tonicization: Bb 12 3
No imitation; more homophonic 16 1
Tonicization: d 17 1
Tonicization: F 27 1
Tonicization: Bb (but deceptive cadence) 28 1
Imitation freer intervalically 31 1
Tonicization: c 33 1
Imitation freer intervalically 46 1
Cycle of 5th? But missing every other root … 71 3
Tonicization: Eb 78 1
Tonicization: F 87 1
Tonicization: Eb 88 1
Tonicization: c 93 1
Tonicization: d 107 1
Tonicization: F 117 1
Homophonic 126 1
Tonicization: c 131 2
Tonicization: c 133 1
Two notes 156 1
Tonicization: Eb 158 1
Repeat 161 1
Tonicization: Eb 163 1
Meter change 166 1
Chromatic ascents 186 1
Meter changes back 186 1
Chromatic descents 191 1
Sequences and double imitation 196 1