Understanding the Andalusian cadence

Four descending chords

The Andalusian cadence, a term borrowed from flamenco, is four chords that go down step by step. In A minor, as here: A minor, G, F and E (Am on the map). It is also called the "descending minor tetrachord": its bass, A, G, F, E, four adjacent notes that fit within a fourth, resembles a tetrachord known since ancient Greece. It can be heard in rock too, for instance in Del Shannon's Runaway.

Under these chords, the map writes i · VII · VI · V: lower case for the minor chord, capitals for the major ones. Elsewhere you will often read i–♭VII–♭VI–V: those flats say that G and F are a half step lower than in A major. The map counts within the A minor scale instead, where they are the seventh and sixth notes.

A G-sharp and a half step

The last chord carries much of the cadence's character. Using only the notes of the A minor scale, the chord built on E would be minor: E, G, B. Here it is major: E, G-sharp, B. That G-sharp, which is not in the key signature, gives the chord its sound, known as "Phrygian dominant".

Listen to the size of the steps, too. The bass goes down a whole step from A to G, a whole step from G to F, then only a half step from F to E. That last small step gives the tetrachord its direction: it pulls towards E. The melody does the same: it reaches the G-sharp by a half step, from A.

What the lesson plays

Sixteen bars in three-four time: the chart four times, one chord per bar. The left hand climbs each chord as an arpeggio, one note per beat: the root, the fifth, then the tenth (the third, an octave higher). On E: E, B, G-sharp. From one bar to the next, the hand keeps its shape and moves down one note with the bass.

• A (bars 1 to 4): the melody descends with the bass, one half note per bar, C, B, A, down to a held G-sharp. It sings the third of each chord, and two eighth notes decorate each half note: the note below, then back.
• A (bars 5 to 8): the same descent; only the last bar changes, E, F, E: the half step, in the melody this time, over E.
• A' (bars 9 to 12): the phrase starts again an octave higher, on that same E-F. Each bar turns around one note, E, D, C, B: the melody still descends with the bass, but now it sings the fifth of each chord. Same chart, different melody: hence the prime.
• A (bars 13 to 16): the opening descent, which comes to rest on a held E.

At the end of each phrase, the map notes an imperfect cadence: the phrase stops on E, the V, hangs in the air and calls for more, the return of Am. In bar 16, nothing comes: the lesson ends on E, left hanging.

How to approach it

My plan takes you through it in 7 days. The goal: to keep this descent in your ear and under your fingers.

1. Sing the bass before you play: A, G, F, E, three beats each. Listen to the last step, shorter than the others: that is the half step.
2. The left hand alone. Set the shape on Am (A, E, C), move it down as it is, then jump back up to A for each phrase. On E, do not forget the G-sharp, the only black key in the lesson.
3. The right hand's eighth notes, the "fast runs" I point out in bar 5: at 132 beats per minute, they go by at 4.4 notes per second. Work on them slowly and evenly; they come back in the first three bars of every descent.
4. The octave leap in bar 9, the other passage I point out: from the E that ends the second phrase to the high E that opens the third. Prepare it during bar 8, with your eyes on the landing note.
5. Hands together, slowly, with a slight lean on the first beat, where the bass falls. Then work up gradually to tempo.
6. Then improvise. Keep the left hand looping and make up your own melody with the A minor scale, turning G into G-sharp over E.