Lessons · Musicianship

Ground bass

A passacaglia: variations over a repeating floor

% A GROUND BASS is a bass phrase that repeats unchanged while
% everything above it is rewritten. This is the lament ground: 1 walks
% down chromatically to 5, and 5 is then held three times as long.
 
bpm 50
instrument swell
key d min
 
Ground<bass> ::= .1 _2 ..7# _2 ..7 _2 ..6# _2 ..6 _2 ..5 _6
 
Ground Ground
 
 
% Variation 1: one voice note per bass note, a tenth above each of
% the five falling ones, then a 4-3 suspension over the held dominant.
 
Descant ::= 3 _2 2 _2 2 _2 1 _2 1 _2 1 _2 .7# _4
 
{Ground, Descant}*2
 
 
% Variation 2: DIVISIONS, the old word for breaking a ground's
% harmony into running notes. Two notes per bass note spell one chord
% each: Dm, viio, Am, G, Bb, then a five-note turn onto the dominant.
 
Divisions ::= 3 5 4 2 5 2 4 1 3 1 2 3 2 1 .7# _2
 
{Ground, Divisions}*2
 
 
% Variation 3 halves the divisions and states them twice: thirty
% notes where there were fifteen, over a ground that has not moved.
 
assert {Divisions}/2 {Divisions}/2 == {Divisions Divisions}/2
 
{Ground, {Divisions}/2 {Divisions}/2}*2
 
 
% Variation 4 stacks both upper voices, the divisions an octave up
% so the descant sits between them and the bass.
 
{Ground, Descant, Divisions@12}*2
 
 
% The passacaglia entire: six statements of one bass line, thinnest
% to thickest, nothing above it repeating until the descant returns.
 
Ground
{Ground, Descant}
{Ground, Divisions}
{Ground, {Divisions}/2 {Divisions}/2}
{Ground, Descant, Divisions@12}
{Ground, Descant}

% A GROUND BASS is a bass phrase that repeats unchanged while
% everything above it is rewritten. This is the lament ground: 1 walks
% down chromatically to 5, and 5 is then held three times as long.

bpm 50
instrument swell
key d min

Ground<bass> ::= .1 _2 ..7# _2 ..7 _2 ..6# _2 ..6 _2 ..5 _6

Ground Ground

% Variation 1: one voice note per bass note, a tenth above each of
% the five falling ones, then a 4-3 suspension over the held dominant.

Descant ::= 3 _2 2 _2 2 _2 1 _2 1 _2 1 _2 .7# _4

{Ground, Descant}*2

% Variation 2: DIVISIONS, the old word for breaking a ground's
% harmony into running notes. Two notes per bass note spell one chord
% each: Dm, viio, Am, G, Bb, then a five-note turn onto the dominant.

Divisions ::= 3 5 4 2 5 2 4 1 3 1 2 3 2 1 .7# _2

{Ground, Divisions}*2

% Variation 3 halves the divisions and states them twice: thirty
% notes where there were fifteen, over a ground that has not moved.

assert {Divisions}/2 {Divisions}/2 == {Divisions Divisions}/2

{Ground, {Divisions}/2 {Divisions}/2}*2

% Variation 4 stacks both upper voices, the divisions an octave up
% so the descant sits between them and the bass.

{Ground, Descant, Divisions@12}*2

% The passacaglia entire: six statements of one bass line, thinnest
% to thickest, nothing above it repeating until the descant returns.

Ground
{Ground, Descant}
{Ground, Divisions}
{Ground, {Divisions}/2 {Divisions}/2}
{Ground, Descant, Divisions@12}
{Ground, Descant}

running…edit it and it re-runs as you type

Ground bass · Musicianship