Simplified CAGED Shapes

The CAGED shapes as we know it so far, with the full chords:

Stripping the above chord shapes of everything but the roots (marked ‘R’) gives us the following:

The Major Scale

You should already familiar with this basic major scale shape:

The positions of the roots in this scale match the ‘E’ shape in the CAGED system.

Accordingly there are four other standard major scale shapes which fit around the roots of the remaining shapes ‘C’, ‘A’, ‘G’ and ‘D’. Here is a complete diagram of the major scale shapes in the CAGED system. Each scale fits perfectly within the octave shapes

Below is the same diagram but with a few notes added in grey. These grey notes are outside the octave shapes but are still notes of the scale.

The Minor Pentatonic Scale

The minor pentatonic scale is one of the first scales we learn, and is certainly one of the most common scales in the majority of guitar music. Its definitely a good idea to learn the minor pentatonic in all CAGED positions. Note how these shapes also built off the CAGED octave shapes.

If you just want to know the scale shapes then the above diagrams are all you really need to know, but those interested in knowing how I arrived at those shapes can read on.

(Very Brief) Theory

For a fretboard map of the C major scale, we need the notes C, D, E, F, G, A, and B in all of their different possible occurrences on the fretboard. (Understanding which notes belong to what scale is beyond this article but I’ll make a post on major scale construction in the near future).

By referring to ‘Finding the Notes Part 1′ and ‘Finding the Notes Part 2′ you can locate every possible occurrence of the seven notes of the C major scale.

But realistically there will be precious few readers who can actually be bothered figuring it all out on their own, so here is a complete diagram to move things along (complete for for 25 frets).

This large fretboard map is a little difficult to comprehend as a whole. The next step is to break it down into its logical parts – one scale for each octave root shape.

… And Ta-Da we’ve found the CAGED shapes!

P.S. Terminology

The CAGED shapes can also be referred to by position numbers, however the numbering system isn’t very intuitive since the numbering starts from the letter ‘E’ in CAGED, rather than sensibly starting with the letter ‘C’.

So…

• Position 1 refers to the ‘E’ shape chord or scale
• Position 2 refers to the ‘D’ shape chord or scale
• Position 3 refers to the ‘C’ shape chord or scale
• Position 4 refers to the ‘A’ shape chord or scale
• Position 5 refers to the ‘G’ shape chord or scale

Why is the numbering system and the CAGED system so un-intuitively incompatible? I honestly don’t know and unfortunately we’ve just got to accept it and deal with it.

Although many people will use the numbering system from time-to-time, on this site I generally refrain from using it. Using the numbering system instead on the CAGED system can get very confusing very quickly – especially when we study the 3NPS scale fingerings which are numbered slightly differently again!

Distortion

The main aspects of distortion as it relates to tone are:

1. Type of Distortion – Hard or Soft Clipping
2. Symmetrical or asymmetrical distortion
3. Where the distortion occurs – at the pickups, the amp, the speaker or a combination of all three

Equally important, is the use of EQ to control the distortion ‘voicing’, but we’ll focus on that in the next post.

Types of Distortion

Its easiest to classify harmonic distortion as being ‘hard’ or ‘soft’ (or anywhere in between) and as being ‘symmetrical’ or ‘asymmetrical’. I’m not examining the solid-state versus tube debate, or the odd-order versus even-order harmonic distortion debate. From an engineering standpoint, solid-state devices can be designed to clip in ways very similar to old tube designs, while a poor design – whether tube or solid-state – will always sound pretty bad. There is no definitive difference between the sounds of a solid state or tube amp so listen, and decide for yourself.

‘Hard’ and ‘Soft’ Clipping

‘Clipping’ is what causes the effect of distortion, and gets its name from the peaks of the waveform being ‘clipped’ off.

This is a pure sine wave with no clipping

This is the same wave, but after clipping. The dotted line represents the original sine wave.

‘Hard’ and ‘soft’ refers to how ‘squarely’ the waveform is clipped. A very flat, square clipping characteristic is known as ‘hard’ clipping, and a rounder clipping shape is known as ‘soft’ clipping. Hard clipping is typically more complex, sounds more aggressive, and generates more harmonic content than soft clipping, which sounds more ‘overdriven’ and retains focus. Silicon fuzz pedals are a good example of hard clipping, whilst very early vintage tube/valve guitar amplifiers will give you an idea of softer clipping.

Hard Clipping

Soft Clipping

In the truer sense of the word, soft clipping refers more to the kinds of distortion found in analogue tape devices and the like. Compared to these soft clipping devices even the gentlest overdrive is really a hard-clipping device. But within the realms of guitar devices the softer clipping devices are usually clean amps, clean boosts, tube/FET based distortion units. The harder clipping units usually usually get their distortion from overdriven transitors.

Its important to understand that how hard or soft the clipping is, has little to do with where the ‘gain’ knob is set. The ‘gain’ controls how much clipping you have in the signal, but the actual clipping characteristic is determined in the design of the pedal or amp. Unfortunately most pedals/amps don’t offer a ‘clipping’ control where you can vary the ‘hardness’ and ‘softness’ of the clipping, so this is something you need to be aware of when purchasing you gear.

Occasionally you may come across ’boutique’ pedals or ‘mods’ for commercial pedals which will allow you to have some control over the clipping characteristic. These pedals usually achieve this by having a switch which will add/rearrange clipping diodes in the circuit. These are a great idea if done well, however be aware that these are only available with a switch – you can’t have a ‘knob’ which gradually changes from hard to soft clipping, its usually just one or the other.

Symmetric versus Asymmetric Clipping

So far all of the examples have been symmetric clipping, which is where both sides of the wave form are clipped the same. Asymmetric clipping, on the other hand, is where each side of the wave form can be clipped differently.

Symmetric clipping is more focused and clear, because it is only generating one set of harmonic overtones. Since asymmetric clipping can be hard-clipped on one side, and soft-clipped on the other, it has the potential to create very thick complex sounds. This means that if you want plenty of overtones, but do not want a lot of gain, asymmetric clipping can be useful. For full-blown distortion symmetric clipping is usually more suitable, since high-gain tones are already very harmonically complex.

Asymmetric clipping also seems to create more apparent intermodulation distortion (the bad kind of distortion). Also, since chords have more harmonic content than solo lines, it is a good idea to avoid chord playing whilst using asymmetric clipping. This helps to avoid objectionable levels of intermodulation distortion. Sticking with symmetrical clipping for rhythm parts helps ensure that your tone doesn’t become muddy and unclear.

Generally speaking, asymmetric clipping is believed to sound more like a real tube amp than symmetric clipping, since most common ‘hailed’ tube amp designs clip asymmetrically. However in my experience they both create very good useful sounds for different applications. Also its my understanding that the more expensive tube amps are actually designed to minimise the amount of asymmetry in the waveform.

Here is a clip with various riffs played at different gain levels. Each riff is first played through an Tubescreamer style pedal and then played again through a Super Distortion style pedal. These pedals are almost identical except that the Tubescreamer clips symmetrically and the Super Distortion clips asymmetrically.

MP3 DEMO OF ASYMMETRIC AND SYMMETRIC DISTORTION COMING SOON

Try these pedals out in your local music store if you want to investigate more. Neither of these pedals are fantastic sounding units (IMHO), but they do highlight the differences between asymmetric distortion and symmetric distortion quite well.

The circuits for the TS-808 and the SD-1 are very similar, so if you decide that you like both of these units for different purposes, you could consider buying one of them and then adding a switch to change the diode clipping arrangement. There are plenty or manufactures who produce kits for this kind of mod, and I wouldn’t be surprised if versions of these pedals exist that have a symmetric/asymmetric switch as standard.

One last note about symmetric versus asymmetric distortion, is that typically asymmetric clipping will have a predominant first harmonic, which the symmetric clipping will not. Many guitarists feel that this harmonic is essential to their tone.

My understanding is that a symmetric clipping circuit doesn’t have to have a diminished first harmonic, but just it is common that they do. Similarly not all asymmetric clipping circuits will have a dominant first harmonic, but it is common. This is because push-pull amplifier designs (which normally clip symmetrically), cancel out the even-order harmonics. Single-ended designs (which clip asymmetrically) do not result in the even-order harmonics being canceled out.

Its probably unclear whether those who favour asymmetrically clipping actually prefer the sound of the asymmetrical waveform, or just prefer the sound of the even-order harmonics. Most likely its a combination of each with more than a heavy hand of hoodoo/voodoo placebo effect thrown in there as well. Realistically they are both valid sounds and it just comes down to choice and personal preference.

Where Should the Distortion Occur

Pickups, OD/Distortion pedals, pre-amps, power-amps, and speakers all distort to some extent. The trick to a good tone is to know where the distortion should occur, and how you can combine distortion from different parts of the chain.

Distortion for High Gain Tones

Generally speaking higher gain tones should only have a few parts of the chain distorting since distorting distortion usually only serves to increase the noise floor, and does not create a very musical tone. This means that for very high gain tones you should probably rely mostly on pre-amp distortion or maybe even a separate pedal. Although there are people who will disagree with me on this point, I feel that high-gain tones need a minimum of pickup distortion and minimum power-amp distortion. Any extra distortion in those areas can only lead to increased levels of intermodulation distortion (I can hear the front three rows hissing and screaming “Blasphemer! Blasphemer! How dare he criticise the power-amp distortion?”) .

In some dedicated high gain amps the master section is relatively linear (i.e. introduces very little distortion), so turning up the master volume will still maintain a good clear, heavily distorted tone. But using a distortion pedal with a vintage style amp with the master volume turned up high, will often take definition and clarity away from the tone, and, in extreme cases, will result in a mushy fuzzy sound, with plenty of inter-modulation distortion (that’s distortion that we don’t want, remember?).

Since high-gain tones sound best with most of the distortion coming from the pre-amp, you should try to use a fairly ‘neutral’ pickup – or even a slightly bright pickup (see ‘voicing’ in the next post) – with a clear ‘hi-fi’ sound. Active pickups can work well, but there are plenty of passive pickups which suit perfectly as well – Dimarzio pickups are very common for this, though I have not used them personally.

As for the speaker choice, it is really personal preference. In my opinion a touch of speaker distortion actually works very well even for high gain sounds, but this is kind of counter-logical and you may disagree.

Overdrive for ‘Clean(er)’ Tones

For clean to overdriven sounds the distortion can be spread out through the chain a bit more. Often players will choose a more characterful, and complex sounding pickup (one with plenty of harmonics, thick sounding, or specific EQ etc), combined with a little pre-amp distortion and a significant amount of power-amp and speaker distortion.

For very subtle clean-overdrive, it is often the power section and the speaker distortion which creates richness of tone. However, Dumble amplifiers – a very revered amp among blues players for ‘mild crunch’ – are known for their use of ‘precision’ power-amps. These power amps were designed to create minimal distortion, so Dumble amps got most of their overdrive from the pre-amp.

‘Dirty’ Tones

For a straight-ahead rock tone – very dirty but not ‘high gain’ – I think that the power-stage is perhaps the most important part of achieving a decent tone. I feel that the power section is so important because it is effectively ‘distorting distortion’. In high gain sounds, distorting distortion is a bad idea since the tone is already very complex and adding more distortion simply makes the tone incomprehensible. But in a rock context in works quite well because it makes the sound very dirty and more complex, but because the tone isn’t soaked in huge amounts of pre-amp gain the overall tone still retains some focus. Hence, the tone sounds ‘very dirty’ but doesn’t sound like your using bucket loads of distortion either. (Afterthought: Maybe asymmetrical distortion might help create a ‘dirty but not high-gain’ sort of tone?)

Beware of intermodualtion distortion though when you try this idea. Van
Halen’s dimed ‘brown’ sound is probably as dirty as you can get before you will need to consider changing over to ‘modern’ high gain amps with more pre-amp distortion and less power-amp distortion. In fact, the intermodulation distortion that occurs in the brown sound is actually already very high, so Van Halen used ‘tempered’ tuning to allow him to play chords but still retain some clarity and focus – otherwise his tone may have just become mushy.

Sonny Landreth / Eric Johnson Lead Tone

Another great tone trick where distorting distortion works remarkably well, is running a fuzz pedal in front of an overdrive, or a dirty pre-amp. Usually we use fuzz pedals to create most of the distortion and then set the rest of the chain relatively ‘clean’, however Eric Johnson and Sonny Landreth, among others, use the fuzz pedal combined with an overdrive of some sort, to great effect.

This usually only works well with lead work, since any chordal playing will highlight the intermodulation distortion. Also it tends to work best with clearer sounding single coils as the more complex humbuckers tend to become too muddy with so much layered distortion. Unfortunately this means that you need to deal with single coil noise, combined with lots of distortion. It can be hard to get just right, but when you do it sounds complex, thick and lush, but with surprising clarity.

The Good and the Bad

Unfortunately what makes great tone so elusive is that usually any one change can have good or bad effects, depending on the situation. For instance, in the last post I mentioned how ‘scooping’ (cutting) the mids could create a smoother tone, but might also rob the tone of its ‘balls’; or how boosting the highs could create a brighter, more articulate sound, but might also cause your tone to become ear-bleedingly shrill and ‘ice-picky’.

Complexity vs. Focus / Interest vs. Simplicity

Unfortunately almost every decision you will make for your tone involves some kind of trade-off like this. To make tone decisions easier it’s helpful to think in terms of trading complexity for focus, and trading interest for simplicity.

The more complex your tone becomes, the harder it is for the listener to be able to comprehend what they are hearing. For instance, a twelve string guitar, with fuzz and distortion through two delay units and a hall reverb, would be incredibly complex in theory, but in reality it would simply sound unintelligible. Conversely, the simpler your tone is, the less interesting it becomes. Such as a cheap guitar, with characterless overtones, played in a dead room, and a boom-box instead of an amp.

It’s like language: very simple language is off-putting because it is too simplistic to communicate anything of value; on the other hand, overly flowery and difficult language is equally off-putting since it masks the meaning.

Balancing Complexity, Focus, Interest and Simplicity

Heavy style players usually use very clean pickups – such as EMGs, Dimarzios or similar – because they have a more focused, simpler sound which will respond well to plenty of complex distortion. Blues players on the other hand, will choose a more complex sounding pickup – with plenty of harmonic content and a characterful EQ curve – but have their amps at much lower gain settings, which allows the tone to retain some focus.

Few people choose to use pickups like EMGs for 100% clean tones since the simplistic tone is uninteresting and often described as sounding ‘sterile’. Similarly, few people match a complex sounding pickup like a P-90, with high gain amplifiers, since this usually just results in ‘mush’.

Of course, so far the concepts of complexity, focus, interest and simplicity, are over simplified (ha ha) – but read on through the coming series and you’ll get a better idea of what I mean.

Frequency Response

The guitar is a mid-range instrument, which is the most sensitive part of human hearing – so it is little wonder that we guitarists are so fussy with our tone. The guitar itself (i.e. the wood) resonates strongest in the mid frequencies, also the pickups have an electrical resonance that emphasises the mid frequencies even more. Generally speaking, humbuckers will have a stronger mid-emphasis than single coils.

In contrast, guitar amplifiers are very lacking in the mids – guitar amplifiers are ‘scooped’. This is one of the reasons why electric-acoustic guitars sound so unnatural when amplified through conventional guitar amps (electric-acoustic guitars require specific ‘acoustic’ amps). Turning the ‘high’ and ‘bass’ knobs all the way down, and the ‘mid’ knob all the way up, will give you a fairly ‘flat’ response and a rough impression of the actual guitar sound without the mid scoop of the amp.

The last aspect of a basic lead setup is the speaker cone(s). These typically have very limited upper frequency response. Amp cabinets with ‘full-range’ speaker systems would sound incredibly harsh and/or fizzy, so guitar speakers are deliberately made to be ‘lo-fi’ (low-fidelity).

These various cuts and boosts at different frequency areas can all affect the final guitar tone in good and bad ways. Swapping in a wider-bandwidth speaker, for instance, may increase clarity and ‘bite’ but could also increase harshness and fizz. Dropping the mids on the tone-stack might ‘smooth’ out the sound, but could also cause your tone to lose its impact, power or ‘balls’.

Distortion

The three parts of the signal chain described above (guitar/pickups, amplifier, speakers) also introduce harmonic distortion. Usually just called distortion, or overdrive, harmonic distortion is a non-linear compression of an audio signal. This means distortion introduces overtones/harmonics into the signal that were not already there. In short, pickups, amplifiers and speakers add upper frequency content to the signal.

It is important to understand that this is not the same as simply boosting the higher frequencies, such as turning up the ‘high’ knob on the tone controls. This is not boosting audio that was already present in the signal, but is actually changing (i.e. distorting) the signal so that the audio coming out is harmonically different from the audio that went in.

Although everybody is familiar with the distortion available with the ‘gain’ knob on the amp, many people don’t realise that pickups and speakers distort as well. Wide-bandwidth pickups (such as active pickups) sound very clean (some people even describe them as ‘sterile’). By contrast, a P-90 will have a much more complex tone, partly as a result of extra harmonic content. Also, a P-90 has a far more ‘middy’ and ‘peaky’ response while an active pickup has a much flatter response, so this also contributes to the sonic differences between the two.

Also, it is common for people to talk about pickups as being ‘dynamic’ or ‘compressed’. It is usually the case that the more ‘compressed’ the pickup is, the more distortion it introduces. Similarly, a more ‘open’ or dynamic pickup will usually impart less distortion.

Speakers also distort, especially when driven hard. Usually this means very high volumes, though guitar speaker manufacturers may deliberately make speakers which will distort at lower volumes.

Basic guitar tone is a result of controlling distortion and controlling the overall frequency response of the signal along the chain.

But What If I Don’t Use Distortion?

Even guitarists who play with a ‘clean’ sound usually have some distortion – it’s just very subtle, and often imperceptible. It is usually a subtle, controlled use of distortion that makes a clean sparkly tone, rich and complex rather than dull, lifeless and sterile. Remember, harmonic distortion is simply harmonic content that was not originally present in the signal. That does not mean that distortion needs to be ‘in-your-face-high-gain’ type distortion. You can use subtle distortion to ‘warm up’ and thicken’ clean sounds too.

In ‘Lead Guitar Tone Part 2′ I’ll mostly be discussing the non-subtle type of distorted lead sounds, but in ‘Lead Guitar Tone Part 3′ I’ll talk about the subtler kinds of distortion that clean players can make use of too.

Attack Characteristics and Compression

Along with distortion and frequency response, the attack characteristic (aka ADSR envelope) is another key factor in how we perceive a guitar’s tone. Depending on the listener/player, the attack characteristic can be a subtle after-thought, or an integral key to the person’s tone.

For guitarists, the attack characteristic is probably best described by how well a sound ‘jumps’ out of the speakers. The key to achieving a highly dynamic sound is to use very dynamic (open) pickups. Looking around online forums etc, I’ve found that most guitarists seem to prefer a highly-dynamic pickup. Open pickups will respond well to playing dynamics – stronger pick attack can drive an amp into a smooth overdrive, whilst a lighter touch can clean up well for rhythm sections. The downside to highly dynamic pickups is that, with a medium overdrive setting, the attack will likely be significantly more distorted than the sustained part of the note. Also, distortion compresses most of the dynamics out of a tone, so dynamic pickups will be of little advantage to a high-gain player. Generally speaking then, you are going to get the most benefit from pickups with a wide dynamic range, if you are using clean(er) tones.

Closely related to attack characteristics is the issue of compression. Compression is anything which serves to reduce the dynamic range of the final signal. This can include heavier strings, higher-output pickups, amplifier overdrive, distortion from pedals, heavy speaker materials, and of course dedicated compressor pedals.

The benefit of signal compression is that it raises the average level of the signal, and can also increase the perceived level of the signal as well. This means that compression makes your tone seem louder! Unfortunately, because compression is effectively reducing the dynamic range of the signal, it has the significant drawback of reducing the expressivity and musicality that can be achieved with sensitive and dynamic playing.

Controlling/manipulating the compression and attack characteristics of your final tone is something that you should do as a final touch on an already stellar tone. In a recording environment, this would mean doing it ‘in the mix’ after you’ve recorded the uncompressed guitar tone. Essentially altering the attack, or adding compression, has the potential to increase the immediacy and impact of the tone, but could also have the opposite effect of robbing the tone of its expressive potential. I’ll talk more about compression and attack in another post in this series, with some specific tips, tricks, dos and don’ts.

Summary

Controlling basic tone comes down to knowing:

1. How much distortion – high gain or low gain
2. What kind of distortion – symmetric or asymmetric
3. Where in the signal chain the distortion occurs – at the pickups, the amp, the speaker or a combination of all three
4. Which frequencies are distorted the most – distortion voicing
5. Which frequencies are dominant
6. Which frequencies are subdued
7. Attack characteristics
8. Dynamic range

P.S. Intermodulation Distortion

Before we finish up, I need to make a quick note about ‘intermodulation distortion’. This is the main distortion that we don’t want. Intermodulation distortion is the effect where signals at different frequencies combine to create signals at other, musically unrelated, frequencies.

Harmonic distortion (the good distortion) creates frequencies which we perceive as being musically related, and are pleasing to the ear (the frequencies conform to the harmonic series). However, the extra frequencies that occur in intermodulation distortion are not based on the harmonic series, and the human ear perceives it as sounding out-of-key.

The greater number of frequencies that occur simultaneously, the greater chance of noticeable intermodulation distortion. Meaning that harmonically complex signals produce stronger intermodulation distortion. Overdrive, fuzz, and ‘distortion’ pedals create their effect by increasing the harmonic content of the signal, so these pedals all increase the likelihood of objectionable intermodulation distortion. Amplifier distortion, compression, speaker distortion and virtually any kind of signal processing (such as reverb or delay) can also lead to an increase in apparent intermodulation distortion.

So, for now, the rule of thumb is to keep your distortion levels down as much as you can get away with (actually that’s good advice for other reasons too which we will soon discover). Later on, though, we’ll look at other ways of combating intermodulation distortion.