Archive for the ‘Music Theory’ Category

Prepping for upcoming gigs – an approach to decoding and transcribing

February 7, 2013 by John No Comments »

I’ve spent a lot of time in the past few weeks preparing for upcoming shows with both of my bands. In the case of the Dudley Manlove Quartet, many of our songs are requests from customers who hire us for private events. Those requests tend to us to recreate a specific arrangement of a song. Case in point for this week is the request for “Love is All Around”, originally performed by The Troggs, and recently reworked by Wet Wet Wet. The customer that made this request specifically asked us to refer to the newer version.

Here are the steps I took in working up the arrangement:

  1. I find the song on YouTube or Pandora and give it a listen from end to end, observing the general arrangement and noting any especially challenging aspects. I don’t attempt to do this with my guitar in hand; I just focus on hearing what the song sounds like.
  2. I sit with my guitar and start to determine the basic framework of the chord structure. I sketch it out using a free software application for music notation called “MuseScore”. I can usually establish the general framework of a song in a few repeat listenings.
  3. If we’re changing the key of the song – which we do pretty frequently – MuseScore can do that automatically after the score is written, but I like to know that in advance because sometimes it makes the song much more difficult to perform in the new key. Once that’s locked down I proceed to the details. For “Love is All Around” the recorded version of the song is in Bb. I was tempted to move it down to A because it would sound so much better on guitar using open string crossings, but we decided to keep it in Bb.
  4. Most songs we perform have idiomatic passages and solos that need to be performed verbatim. I’m very detail-oriented for these elements and explicitly transcribe solos. Putting the effort into really decoding the solo makes a big difference in performing it with authenticity. The song I was transcribing for this event doesn’t have a solo, but there is a little descending guitar lick before the chorus that required a few repetitions to play smoothly. It’s just parallel 6ths, but I want to get the same phrasing as the recording.
  5. Finally, I publish the finished score as a PDF and print a copy for the gig. Usually by the time I’ve gone to all the trouble of writing out the score I’ve already memorized it, but there is something reassuring about having it as a reference before we hit the stage.

By the way, when I first starting doing this process back in my early 20’s, this seemed impossibly difficult and took me a long time. I’ve been transcribing my own parts for a long time and it’s become a big part of how I approach learning music, and after you do it for a few years it becomes much easier. Jazz musicians will tell you: transcribe transcribe transcribe. I completely agree! It’s a very good way to really understand a composition or solo.

 

Twang Man

February 18, 2009 by john No Comments »

My trusty telecaster has been doing a reasonable job since I got it years ago, and it’s a workhorse guitar. It’s always seemed nasal, bright and twangy, which is what I normally associate with those guitars. Lately I’ve really been paying attention to the awesome playing and guitar tone of friend (and fellow 1-Upper) Kris. He’s a very talented guitarist and no matter how good a day I think I’m having as a guitarist, when we play country together I’m eating his dust. The more I listen to his playing, his tone really strikes me as being supremely great and beefy. I’m aware that tone is a function of the musician as much as the guitar, but my telecaster sounds thin and has poor intonation… it seems like there must be a few adjustments that could help it along. So a few weeks ago I asked Kris to take my guitar home with him and make any recommendations toward improving it. I received his response via email within hours of handing it off. His laundry list of recommended changes included new pickups, new bridge, new saddles, and a new output jack. Fortunately the wood parts seem OK 🙂

So I have ordered a set of Lollar Vintage T pickups, the Joe Barden replacement bridge with 3 compensated saddles, and an electroset jack to replace the pesky standard tele jack. Kris is also a good guitar tech and has kindly offered to install the new components. I’m really looking forward to putting it through its paces at our upcoming gig.

 

Intonation On Guitars – Is It Really In Tune?

July 23, 2008 by john 2 Comments »

As guitarists and bassists develop better technique, we often discover there seem to be tuning inconsistencies with our instruments that can’t be addressed by plugging into a tuner. Over the years that I’ve played, I have discovered that there is an inherent problem with all of my instruments in a certain portion of the fretboard range. In the process of trying to understand the problem space, I had to do a little math and physics. See? Beneath its firebreathing veneer of rebellion and self-expressive freedom, rock and roll is actually science! And all this time we thought we were being so anti-establishment. Well, at least we can say we’re putting our science to work.

Let’s start at the beginning of the problem with “this thing isn’t in tune”… these issues need to be fully addressed before we can derive any benefit from discussion on microtuning.

Tuning Issues
If you find your guitar or bass won’t play in tune, there are several things worth examining.

  1. First of all, make sure your strings are relatively new (less than one month old). Old strings, especially if they’re really dull looking and cruddy, will not properly stay in tune. If in doubt replace them and allow the new ones to stretch a bit before proceeding.
  2. How is the neck relief? Sight down the guitar fretboard, looking from the bridge to the nut. If you see an obvious bow / curve / twist in the fretboard, you need to adjust the neck relief. You should also be able detect any serious fret problems this way (see #4 below). Adjusting the neck relief isn’t terribly difficult, but if you aren’t experienced in making this adjustment I’d suggest you have a luthier show you how it’s done. The key here is to make SMALL adjustments; no more than 1/4 turn of the adjustment nut at a time. Warning: overtightening can break the truss rod, and this is the very definition of the word “bummer”.
  3. Your tuning issues might be due to improper string action. Check the height of the string above the fretboard. If there is too much distance from the string to the top of the fret, there will be too much deflection when you fret (you’ll always be pulling the string sharp when fretting). This needs to be adjusted at both the bridge and at the nut. Adjusting the bridge is simple. Adjusting the nut slots is not. I recommend you have a luthier handle any nut adjustments.
  4. It could also be your frets. If the frets are improperly crowned you’ll find tuning isn’t consistent on fretted notes. Sight down the fretboard and take notice of any unusual frets. If you see deep ruts in the frets or they seem really tall, flat, or radically different from each other, it might be time to ask a good luthier for an assessment.

So if you’ve checked all these things and carefully tuned the open strings with a good tuner, only to find your guitar or bass still doesn’t seem in tune when you’re playing, it might be time to check your intonation.

Read the rest of this post for more information… read more…

 

Music and Physics: What Does It Mean To Be "In Tune"?

May 18, 2007 by john 10 Comments »

Most people probably have an innate understanding of what it means to be “in tune”. Generally we define this as the state in which a musical sound seems to match or harmoniously complement another musical sound. In Western musical theory (that is, the music of the western hemisphere, not “western music”) we have a well-established set of fixed musical notes with 12 chromatic notes per octave. The notes on a piano or a fretted instrument such as guitar are (1) fixed quantized values assigned to a key or fret position and (2) compose a set that is consistent within and across these instruments, so if you play middle C on a piano and middle C on a guitar they will be the same pitch and therefore the same note.

So, are the notes on these instruments in tune? The answer is yes. And no.

This post is long, and is a core part of the music theory postings on this site. Read on for details.

Vibrations and Measurement
In the most basic physical sense, all sound results from an object that is in motion. For example, when you pluck the string on guitar, it begins to vibrate. This causes the air in the room to vibrate and our ears detect this vibration, relaying a message to the brain that sound is being heard. The brain perceives physical waveform characteristics of the vibrations such as pitch, loudness, and timbre. The guitar string’s vibration continues, decaying over time until it can no longer be heard.

One commonly used term to describe musical sound is pitch, meaning “how high or how low” a note sounds. The relative highness or lowness is our interpretation of the number of times an object is vibrating during a period of time. We use the physics unit “Hertz” (or Hz) to describe the number of vibratory cycles per second. A higher pitched musical sound has more vibrations per second than a lower one. The human ear detects vibrations from about 15 Hz to 16 KHz, giving us a range of human-detectible pitches to use in music. One of the common tuning standards for pianos, guitars, and symphonies is the pitch 440 Hz. This pitch corresponds to the note “A”, and is commonly referred to as “A440″.  It is worth noting that the A440 standard is not universal; this happens to be the most common tuning standard but there are notable variations in the symphonic world, generally varying by less than 5 Hz. For the sake of simplicity, we will confine our discussion to the A440 tuning standard.

The Mathematics of Harmony
Music consists of pitches (notes), played one after the other. In simple early forms of music, only one pitch is used at a time, even though more than one voice or instrument may be sounding that pitch simultaneously (musicologists call this “homophony”). When a second pitch (“harmony”) is used at the same time, our brain interprets the results of the combination of these two pitches. Some two-note harmonies are considered pleasing (consonant) and others are considered less pleasing (dissonant). Most people find certain precise combinations as particularly pleasing, and there is a mathematical principle behind this.

You were probably introduced to Pythagoras (580 BCE – 505 BCE) at some point in your education. He was the Greek scholar most famous for the Pythagorean Theorem which states that the sum of the squares of the two legs of a right triangle is equal to the square of the hypotenuse. Pythagoras believed that the fundamentally simple principles of geometry and musical harmony could explain the fabric of the universe. According to legend, his musical discovery first occurred when he heard the sound of four blacksmith’s hammers striking anvils. Certain pairs of the hammers sounded consonant and other pairs dissonant:

  • A + B = consonant
  • A + C = consonant
  • A + D = the same note
  • B + C = dissonant

To understand further, Pythagoras weighed the hammers. Each weighed a number of “units” (some say that Pythagoras used the standard pound for this, but it is irrelevant which unit of measure is used as long as it is constant).  He determined that their relative weights could be expressed as follows:

  • A weighed 12 units
  • B weighed 9 unit
  • C weighed 8 units
  • D weighed 6 units

When two hammers were struck at the same time, their relative weights could be expressed as a ratio:

  • A + B = 12:9 (or 4:3)
  • A + C = 12:8 (or 3:2)
  • A + D = 12:6 (or 2:1)
  • B + C = 9:8

Based on the ratios of the mass of these hammers, he discovered a series of mathematical relationships between musically harmonious note intervals. His subsequent experiments were conducted using a simple instrument called themonochord. The monochord consists of a single string stretched between two stationary supporting endpoints, with a movable bridge in the middle, dividing the string into two segments. If the bridge is in the exact center of the string length, the two segments will be exactly the same length with a ratio of 1:1, and therefore the same pitch will sound. If the bridge is moved, the two segments will have different lengths, and therefore different pitches. Pythagoras discovered that certain ratios of string lengths would result in pitch combinations that were especially consonant.

  • 1:1 Unison
  • 2:1 Octave
  • 3:2 Perfect Fifth

If you hear these Pythagorean harmonies, you will almost certainly agree that they are very much in tune and sound pleasing. The Pythagorean-tuned perfect fifth is richly consonant, so we assume it must be in tune. Using just these three simple harmonic ratios, we can explore the Pythagorean scale, beginning at A440 and ending at the note one octave above it. We’ll use the ratio of the Perfect Fifth (3:2), moving around of the circle of fifths to fill out the notes of our scale until we arrive back at the note A again. There are 12 notes in the chromatic scale, so this will require 12 repetitions of the 3:2 ratio, each continuing from the previous note.

  • We identify our starting pitch as A440. By definition, the octave note A’ will have a 2:1 ratio to the starting note A.
  • Expressing this octave relationship mathematically, we have (440 Hz *2) = 880 Hz.
  • This defines the frequency range of our octave. We know that all our notes will fall in between 440 Hz and 880 Hz.
  • Each n step around the circle of fifths results in a frequency f whose formula can be mathematically described as
    f = (((3:2)^n) x 440 Hz),  and we can apply the 2:1 octave rule when necessary to keep our resultant frequency f within our 440 Hz < f < 880 Hz spectrum.

With these rules we will begin building a table of pitches for our Pythagorean scale.

Note Name Ratio From A440 Frequency
A 1:1 440 Hz
A’ 2:1 880 Hz

So far so good. Let’s go ahead and add our next note, the perfect fifth. The note E is a perfect fifth above A, with a pitch ratio of 3:2 from our starting note A440
Here is the mathematical formula for computing the value: (440 Hz*3)/2 = 660 Hz

Note Name Ratio From A440 Frequency
A 1:1 440 Hz
E 3:2 660 Hz
A’ 2:1 880 Hz

We’ll continue by adding our next note. The note B is a Perfect Fifth above E, with a ratio of 3:2 above its frequency.
Math: (660 Hz*3)/2=990 Hz
This is above 880 Hz, our highest frequency in the octave. We want to get a B note in the same octave range as the original A note, so the frequency should fall between 440 Hz and 880 Hz. Remember that all octaves have a 2:1 ratio, so our B note at 990 Hz can be divided by 2 to get 495 Hz, the same pitch, but one octave lower.
Our ratio from the starting A440 note is ((3:2)^2)/2 or 9:8

Note Name Ratio From A440 Frequency
A 1:1 440 Hz
B 9:8 495 Hz
E 3:2 660 Hz
A’ 2:1 880 Hz

The note F# is a Perfect Fifth above B, with a ratio of 3:2 above its frequency.
Math: (495 Hz *3)/2 = 742.5 Hz
The ratio from the starting A440 note is (3:2)^5 or 27:16

Note Name Ratio From A440 Frequency
A 1:1 440 Hz
B 9:8 495 Hz
E 3:2 660 Hz
F# 27:16 742.5 Hz
A’ 2:1 880 Hz

The note C# is a Perfect Fifth above F#, with a ratio of 3:2 above it.
Math: (742.5 Hz*3)/2 = 1113.75 Hz
To keep this note in the same octave we divide by 2, which gives us 556.875 Hz
The ratio from the starting A440 note is now (3:2) ^4 or 81:64

Note Name Ratio From A440 Frequency
A 1:1 440 Hz
B 9:8 495 Hz
C# 81:64 556.875 Hz
E 3:2 660 Hz
F# 27:16 742.5 Hz
A’ 2:1 880 Hz

The note G# is a Perfect Fifth above C#, with a ratio of 3:2 above it.
Math: (556.875 Hz*3)/2 = 835.3125 Hz
The ratio from our starting A440 note is now (3:2)^5 or 243:128

Note Name Ratio From A440 Frequency
A 1:1 440 Hz
B 9:8 495 Hz
C# 81:64 556.875 Hz
E 3:2 660 Hz
F# 27:16 742.5 Hz
G# 243:128 835.3125 Hz
A’ 2:1 880 Hz

The note D# is a Perfect Fifth above G#, with a ratio of 3:2 above it.
Math: (835.3125 Hz*3)/2 = 1252.96875 Hz
Divide by 2 to get 626.484375 Hz
The ratio from our starting A440 note is now (3:2)^6 or 729:512

Note Name Ratio From A440 Frequency
A 1:1 440 Hz
B 9:8 495 Hz
C# 81:64 556.875 Hz
D# 729:512 626.484375 Hz
E 3:2 660 Hz
F# 27:16 742.5 Hz
G# 243:128 835.3125 Hz
A’ 2:1 880 Hz

At this point we have the diatonic notes (those notes considered as members of the normal set) for the A Major scale. It looks like we’re on track here. But let’s continue with our exercise. Remember that there are 12 chromatic pitches in Western music theory. Starting with the last note we added (D#), let’s continue with computing the rest of the chromatic notes.

The note A# is a Perfect Fifth above D#, with a ratio of 3:2 above it.
Math: (626.484375 Hz*3)/2 = 939.7265625 Hz
Divide by 2 to get 469.86328125 Hz
The ratio from our starting A440 note is now (3:2)^7 or 2187:2048

Note Name Ratio From A440 Frequency
A 1:1 440 Hz
A# 2187:2048 469.86328125 Hz
B 9:8 495 Hz
C# 81:64 556.875 Hz
D# 729:512 626.484375 Hz
E 3:2 660 Hz
F# 27:16 742.5 Hz
G# 243:128 835.3125 Hz
A’ 2:1 880 Hz

The note E# is a Perfect Fifth above A#, with a ratio of 3:2 above it.
Math: (469.86328125 Hz*3)/2 = 704.794921875 Hz.
Divide by 2 to get 352.3974609375 Hz
The ratio from our starting A440 note is now (3:2)^8 or 6561:8192.

Note Name Ratio From A440 Frequency
A 1:1 440 Hz
A# 2187:2048 469.86328125 Hz
B 9:8 495 Hz
C# 81:64 556.875 Hz
D# 729:512 626.484375 Hz
E 3:2 660 Hz
E# 6561:8192 352.3974609375 Hz
F# 27:16 742.5 Hz
G# 243:128 835.3125 Hz
A’ 2:1 880 Hz

The note B# is a Perfect Fifth above E#, with a ratio of 3:2 above it.
Math: (352.3974609375 Hz*3)/2 = 528.59619140625 Hz.
The ratio from our starting A440 note is now (3:2)^9 or 19683:16384.

Note Name Ratio From A440 Frequency
A 1:1 440 Hz
A# 2187:2048 469.86328125 Hz
B 9:8 495 Hz
B# 19683:16384 528.59619140625 Hz
C# 81:64 556.875 Hz
D# 729:512 626.484375 Hz
E 3:2 660 Hz
E# 6561:8192 352.3974609 Hz
F# 27:16 742.5 Hz
G# 243:128 835.3125 Hz
A’ 2:1 880 Hz

The note F## (F double sharp is enharmonic with G) is a Perfect Fifth above B#, with a ratio of 3:2 above it.
Math: (528.59619140625 Hz*3)/2 = 792.894287109375 Hz.
Divide by 2 to get 396.447143554687 Hz
The ratio from our starting A440 note is now (3:2)^10 or 59049:32768.

Note Name Ratio From A440 Frequency
A 1:1 440 Hz
A# 2187:2048 469.86328125 Hz
B 9:8 495 Hz
B# 19683:16384 528.59619140625 Hz
C# 81:64 556.875 Hz
D# 729:512 626.484375 Hz
E 3:2 660 Hz
E# 6561:8192 352.3974609 Hz
F# 27:16 742.5 Hz
F## 59049:32768 396.447143554687 Hz
G# 243:128 835.3125 Hz
A’ 2:1 880 Hz

The note C## (C double sharp is enharmonic with D) is a Perfect Fifth above F##, with a ratio of 3:2 above it.
Math: (792.894287109375 Hz*3)/2 = 594.670715332031 Hz.
The ratio from our starting A440 note is now (3:2)^11 or 177147:131072.

Note Name Ratio From A440 Frequency
A 1:1 440 Hz
A# 2187:2048 469.86328125 Hz
B 9:8 495 Hz
B# 19683:16384 528.59619140625 Hz
C# 81:64 556.875 Hz
C## 177147:131072 594.670715332031 Hz
D# 729:512 626.484375 Hz
E 3:2 660 Hz
E# 6561:8192 352.3974609 Hz
F# 27:16 742.5 Hz
F## 59049:65536 396.447143554687 Hz
G# 243:128 835.3125 Hz
A’ 2:1 880 Hz

Let’s add the last note to our chromatic scale.
The note G## (G double sharp is enharmonic with A) is a Perfect Fifth above C##, with a ratio of 3:2 above it.
Math: (594.670715332031 Hz*3)/2 = 892.006072998046 Hz.
The ratio from our starting A440 note is now (3:2)^12 or 1062882:524288.

Note Name Ratio From A440 Frequency
A 1:1 440 Hz
A# 2187:2048 469.86328125 Hz
B 9:8 495 Hz
B# 19683:16384 528.59619140625 Hz
C# 81:64 556.875 Hz
C## 177147:131072 594.670715332031 Hz
D# 729:512 626.484375 Hz
E 3:2 660 Hz
E# 6561:8192 352.3974609 Hz
F# 27:16 742.5 Hz
F## 59049:65536 396.447143554687 Hz
G# 243:128 835.3125 Hz
G## 1062882:524288 892.006072998046 Hz
A’ 2:1 880 Hz

So, here we are at the end of all that math, and there seems to be a bit of a problem. G## is enharmonic with the note A, so we expect G## to be the same frequency as A’. As you can see from the chart, these frequencies are not the same. The math is right… we’ve gone all the way around the chromatic scale using the 3:2 ratio provided by Pythagoras, but the octave note is not what we expected.

Why Are These Frequencies Different?
The ratio of G## to our starting A440 is 1062882:524288. This is slightly larger than 2:1 and our octave note has a discrepancy of over 12 Hz from what we expected. This discrepancy is called “Pythagorean Comma”. The notes in the Pythagorean scale sound very much purely in tune, especially when building diatonic chords in the key upon which the scale is based (in this case, the key of A). This scale yields acoustically perfect fifths that are musically satisfying, but it is important to note that the whole tone interval (for instance from A to B) is not equal to the sum of two semitones (A to A# to B). The problem with this approach is that you need to recompute (and thus retune) the intervals for each key based on the starting note. If you happen to be playing a piano that has been tuned to the Pythagorean scale, it sounds beautifully in tune for only one key.  If you change keys, the entire instrument needs to be retuned in reference to your new key center.

During the early Renaissance, composers began to modulate (change tonal centers) to different keys during a composition. Pythagorean tuning produced unacceptable dissonance in these other keys. To alleviate this problem, some alternate tuning systems were devised. One tuning system, the mean tone tuning, made the fifth slightly flat in order to provide acoustically perfect thirds. However, it still suffered from a discrepancy between adjacent semitones. Four of the chromatic keys were closer to perfect acoustic tuning than the other eight. As one modulated key centers successively, the semitone tuning discrepancy became gratingly dissonant.

Equal Temperament
The eventual solution to the tuning standard was to create a system in which

  • Octaves observe the 2:1 ratio and are acoustically in tune
  • All other intervals are acoustically slightly out of tune (tempered), by an amount that is small enough to be considered musically acceptable

With twelve even ratios per octave, we can find the ratio of adjacent tones using the formula:

  • r^12 = 2
    or
  • r=twelfth root of two
    or
  • r=2^(1/12)

Equal temperament divides the octave into 12 equal semitones, using a constant ratio for adjacent semitones. The tuning system was embraced by Bach, most notably in his Well-Tempered Clavier, which comprises 24 preludes and fugues for keyboard (one in each of the 12 chromatic major and minor keys). In order to perform these compositions, the keyboard instrument must be equally tempered to avoid tuning dissonance in most keys. It is interesting to note that equally tempered Spanish guitars were in use before the year 1500, which predates theWell-Tempered Clavier.

So Are We In Tune?
The difficulty in answering this question has a lot to do with our perception of tuning. In the purest acoustic sense, we accept a tolerable magnitude of tuning error in order to allow all musical keys to equally consonant. This is especially true for “fixed” tuning instruments such as piano or fretted guitar.

On some musical instruments it is possible to make small adjustments to notes in order to perfectly tune intervals. These instruments include:

  • Fretless bass
  • Classical strings (violin etc.)
  • Trombone
  • Trumpet (using valve slides)

The Impact of Temperament on Getting Guitars in Tune
With frets to help quantize pitches, it should be less problematic to tune guitars or basses. Ironically, many guitarists and bassists learn a seemingly handy means of tuning their instruments using harmonics on adjacent strings. Since these instruments are tuned with (most) pairs adjacent strings having the relationship of a perfect fourth, if one sounds the fifth fret harmonic on the lower string and theseventh fret harmonic on the upper string, these notes appear to be sounding in unison. However, remember that:

  • The guitar’s frets are placed in accordance with the equal temperament scale
  • Harmonics belong to the Pythagorean scale of perfect ratios
  • The fifth fret harmonic is producing a note whose ratio above the fundamental is 4:1 (two octaves). This note belongs to both the equal temperament scale and the Pythagorean scale. By definition this note is in tune with both systems.
  • The seventh fret harmonic produces a note whose relationship to the open string is exactly 3:2. This ratio belongs to the Pythagorean scale but not to the equal temperament scale.

Therefore this tuning method will very nearly tune the instrument, but introduces an error whose magnitude is equal to the Pythagorean comma. Granted, this is a very small discrepency that can only be detected by a very sensitive ear. But it’s not in tune, and the tuning error should not be overlooked.

The most reliable means of tuning instruments is to use a “strobe tuner” or other electronic tuner. This ensures that the base intervals are equally tempered, with further “musical tuning” adjustments made during performance at the discretion of the performer.