|
SongTrellis |
|
||||||||||
|
|
|||||||||||
|
Which chords are nearest neighbors? For any type of chord that you choose, there are twelve possible root notes upon which you could construct that type of chord. Those are the 12 notes of the chromatic scale: C, Db, D, Eb, E, F, Gb, G, Ab, A, Bb and B. Choose one of the twelve chords generated on these 12 chromatic roots. Ask yourself which of the other 11 chords sound most related to the chord you've chosen? In almost all cases, your ear will tell you that there are two chords which are the closest relatives of your chosen chord. One of these will be built on the root that is a perfect fifth above the root of your chosen chord. The other will be built on the root that is a perfect fifth below the root of your chosen chord. The closest neighbors have roots a perfect fifth apart For example, if your chosen chord is C7, it will feel like G7, with root a perfect fifth above C, and F7, with root a perfect fifth below C, are the closest relatives to C7 among the 11 chords you could have chosen. If your chosen chord was a Dmi7, the minor 7th chords whose roots are perfect fifth chord above and below D, A mi7 and G mi7 will seem to be the closest mi7 relatives of Dmi7. If you always move by perfect fifth, you will visit all 12 possible roots before you revisit any root. If you pick one of the 12 possible roots, say C, and visit in succession the root that is a perfect fifth lower than the last root you've visited, you'll find that you will visit all twelve of the possible roots without visiting any more than once. You'll also find if you keep going down by perfect fifth, you will visit the same list of twelve roots again in exactly the same order. If you write down this cycle of roots starting with C, the list of roots reads: C F Bb Eb Ab Db Gb B E A D and G. Music theorist call this list of roots the cycle of fifths, although to be more specific it should be called the cycle of fifths descending. Twelve root names is too many to remember in sequence . Is there a good mnemonic? It would be great if there was a neat memorization trick which would let us remember this list of roots. Unfortunately, there are twelve root names to remember. Psychologists figured out quite a while ago that most humans have a pretty easy time keeping seven objects in mind at a time. They also found that when people have to recall lists that have more than seven elements in them, they do a much better job when they can mentally chunk a larger list into sublists containing seven or fewer elements. Is there a way to break the list of roots into two or more chunks that is easier to memorize? Beyond that, is there a way of chunking the list in a way that will help you better understand, analyze and memorize chord progressions that you will encounter in your musical study? Yes,there is a mnemonic that uses seven characters that you can chunk into a group of four and a group of three. It's B-E-A-D-G-C-F I'm going to propose a mnemonic that uses a rearrangement of the seven roots that are in the C major scale. Interestingly, it is possible to write this list of roots in a sequence so that you find the next note in the sequence by descending a perfect fifth from the previous root. This means that we should be able to find this list of seven roots someplace in the cycle of roots that we wrote down above for the cycle of fifths. Here it is: B E A D G C F. To derive this from the original list of cycle roots, I visited the last five roots in the list (B E A D G) and then wrapped around to the beginning of the cycle and visited the first two roots (C and F). How does it work? How does this string work as a mnemonic? Let's write out the complete cycle of 5ths starting with B: B E A D G C F Bb Eb Ab Db Gb. If we look at the first four roots of the cycle, we see an intelligible English word, bead, spelled out. The next three roots don't spell out anything intelligible but are easily remembered since there are only three to memorize. What about the last five roots of the cycle? If you can remember bead-gcf, you can easily derive these roots since we just apply a flat sign to the note names B, E, A, D, and G giving us the Bb,Eb,Ab,Db,and Gb that we need. Actually it doesn't matter if we flat the C and F at the end of bead-gcf since Cb is the same pitch as the B that begins the cycle and Fb is the same pitch as the E which comes next. Is there a musical meaning buried in the BEAD-GCF mnemonic? Is there helpful musical meaning buried in this ordering of seven roots taken from the C major scale? Yes. Actually, there are several. 1) These are all of the notes of the C Major scale. 2) These are chords that can be built using only the notes of the C Major scale as roots. If you arrange their roots according to the order of roots in the mnemonic, your ear travels from far away chords to those that sound closer and more related to the C Major chord. It's possible to build three, four , or five note chords on top of these chord roots, so that each of the notes of the chord is drawn only from the notes of the C major scale. Because the scale steps in the C major scale are not of uniform size (there are 5 major 2nds and two minor 2nds), no one type of chord can be built on all of the notes of the scale. Let's assume we are building four note chords on each scale step named in the mnemonic. We would find that a Bmi7(b5) uses only the pitches B,D, F and A. We would find that the Emi7 uses only E G B and D. The Ami7 would use only A, C, E, and G. The Dmi7 would use only D, F , A, and C. The G7 would use only G, B, D and F. The CMA7 would use C E G and B. The FMA7 would use F, A, C, and E.. If you lay out these seven chords in cycle of 5ths sequence, you'd see Bmi7(b5), Emi7, Ami7, Dmi7, G7, CMA7 and FMA7. If you play these chords in sequence, they seem to lead your ear naturally from chord to chord till the C MA7 is reached. Continuing to FMA7 seems to overshoot the goal but if you come back to CMA7 at the end your ear will most likely feel satisfied. 3) Imagine you are improvising in C Major, choosing to play notes that are only in the C major scale. Say you want to change one note so that your playing in the closest neighboring keys, F Major or G Major. The mnemonic will let you identify which note you'll need to alter without having the recall the entire spelling of the notes in the next key. Lay out the 12 notes of the cycle of fifths on one line of a sheet of paper in the order prescribed by our mnemonic and then copy the sequence again: B E A D G C F Bb Eb Ab Db Gb B E A D G C F Bb Eb Ab Db Gb Pick any adjacent seven note sublist from this larger list. These will be the notes of one of the 12 Major scales. Imagine that you've spaced the note names equally and that you have constructed a device which obscures all notes except the seven adjacent notes of a particular major scale. If you are looking at B E A D G C F and slide your device one position to the right, you will see that the leftmost note name B will become hidden and a new note, Bb, will be revealed. This will tell you can change a C Major scale into an F Major scale by flatting the B in C Major and replacing it with the Bb which is part of F Major. It's instructive to analyze the note names that appear in any seven note window of the cycle of fifths. If you do this for C Major, we have the pitch names B E A D G C F. We can create a different list by translating each of these pitch names into a list of numbers that identifies where that note appears in the major scale. If we do this, we get the numerical list: 7 3 6 2 5 1 4. If we equate these to interval names we discover that this list of numbers identifies the Major 7th, Major 3rd, Major 6th,Major 2nd, Perfect 5th, Root and Perfect 4th. If we translate the remaining five notes in the cycle Bb, Eb, Ab, Db, Gb we have the pitches named 7b 3b 6b 2b and 5b, the minor (flatted) 7th, minor (flatted) 3rd, minor (flatted) 6th, minor (flatted) 2nd and the diminished (flatted) 5th. If we look at the pitches names in our seven note window we discover that the leftmost position in the window is 7, the major seventh, the rightmost position is 4 the perfect 4th, and the next to last position identifies the root of the scale. When we slide the window to the right, we see that we can transform any major scale into its right neighbor by flatting the major 7th pitch of the scale. This flatted 7th note will become the perfect fourth in the new scale. When we slide our seven pitch window to the left, we see that we can transform any major scale into its neighbor on the left, by taking the pitch identified as the perfect 4th and raising it by a half step transforming it into an augmented 4th. This augmented 4th with respect to the original scale will become the major seventh of the major scale that is the left neighbor of the original scale. 4) The major scales are sometimes identified by the number of flats or sharps in the key signature (key of 2 flats, key of 3 sharps). This mnemonic will you to easily tell which notes in the scale are played flat or sharp. The key of F Major is the key with one flat. The flatted note is Bb. As you can see as you add flats you just follow the order of pitch names in the BE AD G C F mnemonic to determine the next note which will have the flat applied to it. For sharps you play the mnemonic backwards (F C G D A E B) to find the order in which sharped notes replace the unsharped notes in the sharp keys. The key of G Major is the key with one sharp, which is F#. 5) The sequence of roots of chords in many tunes follows the order of pitches in the BEADGCF mnemonic. You will see that in many tunes, the roots of chords in the tunes chord progression will spell out some subsequence of root names in the order specified by the mnemonic. One of two modes of root motion following the BEADGCF root order can frequently be identified in classical and popular tunes. In simpler tunes (older classical, hymns, anthems, country and western, rock and roll), one position on the cycle of fifths will be identified as a home position and the progression will start with this home position and then move one root position to either side of this root position. If D were chosen as the home position, a progression might oscillate back and forth visiting D and its closest neighbors A and G like: D G D A D G D. Or it might alternate back and forth visiting only its left neighbor A (as in DADAD) or only its right neighbor (D G D G D). Very frequently a tune will start on home position, jump to the right neighbor, jump back to the left neighbor and then return to home position (D G A D) In more complicated tunes (jazz tunes, show tunes, movie music, newer classical) a home position is chosen on the cycle of fifths. The chord progression will leap several positions to the left and then will visit every stop on the cycle that leads back to the home position. If Eb were picked as home position, a chord sequence might start with Eb, jump back to G and then visit,C, F, Bb back to Eb. When the progression comes back to the home position, the roots on either side of the home position might be visited just as in the simpler root positions. There are responses to this message:
|
|||||||||||
|
Last update: Saturday, May 11, 2002 at 12:48 PM. |
|||||||||||