to extend the answer slightly a pad is a sound
type that is usually used with a musical line that is based on outlining the chord movement.
It may use all of the chord tones or just an outline of the chord usually the root and 5th and octave, sometimes just the root and octave.
It may even construct a much longer counter-melodic line using different chord tones as
the progression moves on, e.g. the chord
progression is I-V-IV-ii-V-I in C major (C-G-F-Dm-G-C) the line could be played in octaves as
C-B-A-A-G-G
or
E-D-C-D-B-C
or
G-G-F-F-D-E
or any one of another 3[SUP]6[/SUP] (729) possibilities (some will be more likely than others)
note that these three lines together contain all of the notes of each chord at each step if lined up together
Chord progression | C | G | F | Dm | G | C |
Chordal pad | C
E
G | B
D
G | A
C
F | A
D
F | G
B
D | G
C
E |
Octaves Only | C'
C | G'
G | F'
F | D'
D | G'
G | C'
C |
Octaves and 5th | C'
G
C | G'
D
G | F'
C
F | D'
A
D | G'
D
G | C'
G
C |
Melodic pad 1 | C'
C | B'
B | A'
A | A'
A | G'
G | G'
G |
Melodic pad 2 | E'
E | D'
D | C'
C | D'
D | B'
B | C'
C |
Melodic pad 3 | G'
G | G'
G | F'
F | F'
F | D'
D | E'
E |