17b Discussion - Harmonic Sequences

Sequence Secrets

Harmonic Sequences:

• A harmonic sequence is when the roots of the chords in a progression are moving like a sequence.
• (remember that the bass notes might not always be the roots!)

“Why do they work?”

• Humans like patterns!
• Sequences don’t have to follow functional progression rules if the motion of the melody follows a strong pattern.

Classification and Labeling:

This process works the same as for melodic sequences

• Look if the roots move by exact intervals, or if they move diatonically. Leadsheet is the secret to spotting sequential root movement!!
• Rather than putting brackets over the notes, you put brackets under the roman numerals.
• You label the interval of transposition the same as with melodic sequences - with an arrow and an interval.

Common sequences:

Parallel 6:

• Made entirely of first inversion chords. Because of this, there’s always a sixth somewhere between the bass and one of the voices.
• The bass is descending in stepwise motion

Pachelbel’s Sequence:

• This sequence transposes down a third every iteration. Each iteration is made up of two chords.
• You can spell the chords in different inversions so that the bass line descends in stepwise motion.
• This is the reason we have iii -> IV in our chord progression chart! This progression works in Pachelbel’s “Canon in D” and is used widely even today.

Andalusian Progression:

• i, ^bVII, ^bVI, V
• Bass line solfege: Do, Te, Le, So
• EXTREMELY COMMON
• Gets its name from the Andalusian Peninsula, which includes Portugal and Spain, because it is a very common sound in traditional music from that area.