+\chords { e1:m e1:7 e1:m7 }
+@end lilypond
+The first number following the root is taken to be the `type' of the
+chord, thirds are added to the root until it reaches the specified
+number, for example.
+@lilypond[fragment,verbatim]
+ \chords { c:3 c:5 c:6 c:7 c:8 c:9 c:10 c:11 }
+@end lilypond
+
+@cindex root of chord
+@cindex additions, in chords
+@cindex removals, in chords
+
+More complex chords may also be constructed adding separate steps
+to a chord. Additions are added after the number following
+the colon, and are separated by dots. For example
+@c
+@lilypond[verbatim,fragment]
+ \chords { c:5.6 c:3.7.8 c:3.6.13 }
+@end lilypond
+Chord steps can be altered by suffixing a @code{-} or @code{+} sign
+to the number, for example:
+@lilypond[verbatim,fragment]
+ \chords { c:7+ c:5+.3- c:3-.5-.7- }
+@end lilypond
+Removals are specified similarly, and are introduced by a caret. They
+must come after the additions.
+@lilypond[verbatim,fragment]
+ \chords { c^3 c:7^5 c:9^3.5 }
+@end lilypond
+
+Modifiers can be used to change pitches. The following modifiers are
+supported
+@table @code
+@item m
+ Minor chord. Lowers the 3rd and (if present) the 7th step.
+@item dim
+ Diminished chord. Lowers the 3rd, 5th and (if present) the 7th step
+@item aug
+ Augmented chord. Raises the 5th step.
+@item maj
+ Major 7th chord. Raises the 7th step, if present.
+@item sus
+ Suspended 4th or 2nd. This modifier removes the 3rd step. Append
+ either @code{2} or @code{4} to add the 2nd or 4th step to the chord.
+@end table
+Modifiers can be mixed with additions.
+@lilypond[verbatim,fragment]
+ \chords { c:sus4 c:7sus4 c:dim7 c:m6 }