Modes in Modern Pop & Commercial Composition
Before reading this make sure you are familiar with the basic concept which is covered in the modes in jazz article. I prefer not to think of modes as relative to a major scale (e.g. D Dorian as a mode of C major), but as a scale in its own right. So D Dorian is based on the note D and functions purely as a D Dorian, and is not a relation of the a C major. This may not be as easy as relating each mode to a major scale with the same notes, but it makes more sense in the end. You need to learn the relationship between each note of the scale and the root as well as each note of the scale and the adjacent note.
Modes can be used freely in pop music, either in a traditional form, as a one or two chord riff (eg modal jazz or riff based pop, funk etc) or as a way of finding interesting chord substitutions as with modal interchange.
Traditional (melodic) use of modes
Typical examples can be found in folk music. As with conventional tonal harmony a chord can be built up in 3rds from a root note, which can be any note of the scale:
Obviously in folk genres we’d want to keep the harmony simple, e.g. using triads rather than 7ths. And in a dorian mode the half diminished on VI would rarely be used.
Note that in this Dorian example the VII chord (C) is used for the final cadence. One of the main features of modal music is the lack of a traditional V7 -I perfect cadence (Except, of course, the Ionian mode which is the major scale). In this example the Am could also have been continued through bar 7 to give a Vm-I cadence.
Modal Jazz & Riffs
If only one chord is used for a tune, it can imply more than one mode, either for composing a melody or for improvising. This ambiguity can be used very effectively to allow the music to shift between different modes (and moods):
If two chords are used as a riff, then they will usually imply a particular mode:
In the following example of a typical Latin riff, the C# is a passing note, so a Dorian mode is still implied, though in improvisation or composition a C# could be used either to coincide with the C# in the riff, or as a neighbour (or “leading”) note.
Modal Interchange
This is where conventional tonal harmony is used but chord substitutions are used which “borrow” chords from a mode – see Modal Interchange. In the following example a bVII chord is used to substitute for a more conventional V7. In this case the D and F in the melody could conventionally have been harmonised with a G7, but in this case on the D note you imagine that you switch temporarily from C major to C Aeolian mode. This contains a chord of Bb7 and as it contains a D and F, can be used to harmonise those notes. It gives a very different flavour.

