During the process of learning the guitar, a lot of us come upon a stumbling block called theory.
I'll try and share what limited knowledge I have, in three parts:
- Notes
- intervals (which will also cover some basic theory on scales)
- chords.
I will not complicate the postings with references of how to find those notes or chords on the guitar fretboard - there are hundreds of web resources that will help you get those, some of them in this thread - check v1gnesh's post for links to beginners' sites.
Or look for Nut chords on
Music Software - Computer Music Resources - Shareware Music Machine
Remember that some of the world's best players knew little to no theory. Howling Wolf and Blind Willie Mctell probably knew very little of conventional theory, but the music they produced was indescribably beautiful and emotional. Would they have produced better music if they knew theory? I don't know - but musicians like them are rare indeed, and a lot of us have to work hard at it. I'm one of those with very little natural talent, so I had to learn a bit of theory to get myself going.
With all that said, let's get moving, shall we?
1. What are notes?
Notes are quite simply, a single frequency that causes a vibration in the air. It can be visually represented by a waveform. Pure notes exist only in instruments created to generate it. Most natural sources emit multiple notes at the same time. This is why instruments and voices sound different from each other, even playing/singing the same note.
Generally, computers (when programmed), tuning forks, pitch pipes etc will generate pure tones. Musical instruments, cars, animals and people will generate complex tones that are a combination of multiple notes, harmonics and distortion.
There is a technical difference between note and tone. Note is a pure frequency pitch, and since most sources don't have a pure single frequency coming off it, the resultant sound is known as a tone. In fact, a note does not really exist in the context of musical instruments, it's only a representative of the main frequency (called the fundamental) that the instrument should emit. But for this stream of thought, we will use the terms interchangeably.
Look at this graph:
http://img256.imageshack.us/img256/6171/graphsdi0.jpg
Notice the difference between the note coming off a computer, guitar and piano. The guitar is the most harmonically rich of the three. That may not be always the case, depending on the specific instrument.
All musical instruments have a harmonically rich structure, yet we play notes, right? Then what is this 'Tone' all about? Basically 'Note' is what you play, and 'tone' is what comes out of the instrument!
Scientists like to refer to tones and frequency, musicians call them notes and pitch. When musicians refer to tone, they're talking about the quality of the sound, not a measurement.
2. Notes, why are they needed?
The same reason you need a liter, or a kilo, or a meter - it's a measure of the pitch of a note. The human ear has an approximate range of 20Hz - 20,000Hz. That is, there are 19,980 possible pure frequencies that can exist (not counting fractions). Can the human ear distinguish all of them?
As it turns out, no. Human hearing is much more sensitive to direction and timing of sound (for example, if that wild beast was coming to eat it) than its frequency (to judge whether said animal was happy or sad).
So we can only detect incremental differences in sound, and our perception gets better as the intervals get bigger. If you play a pure tone at 20Hz and the next one at 20,000 Hz (assuming the listener can hear it, as most people's hearing tapers off to about 10 Khz by the time they're 40), you'll be able to immediately tell the difference. If the same two tones are at 5000 and 5001 Hz, it's pretty certain nobody will know a difference. The surprising thing is that if you play them at the same time, you will immediately hear a pulsation about once a second, and you can tell there are two different tones. We will return to this when we talk about tuning.
Every double of frequency is heard by the ear to be exactly the same thing. Play a G on the open string and on the 12th fret of the 3rd string, they sound the same. They are not the same pitch/frequency, but the ear hears them as the same 'note'. Therefore, every time the frequency doubles, it's known as an 'octave', and the frequencies an octave apart are given the same name.
As you can see on the guitar there are twelve frets, which means an octave is split into 12 parts. Why 12 and not 4 or 24? the answer to this is that it wasn't always like that.
Upto the 16th century, music was primarily orchestral, and written for ensembles. In the ensemble string instruments had to play with fixed pitch instruments like the wind instruments and piano. These were tuned to different temperaments, and the string sections had to adjust their playing to the pitch of those instruments. That is one of the reasons why violins, cellos and upright bass were all fretless. Micro-intonation was not just possible, it was the only way for the string section to play with the winds and pianos.
Soon the emergence of the guitar, vihuela and more 'portable' instruments led to fresh music being written for these instruments, this led to the emergence of 'equal temperament', or the division of the octave into 12 intervals.
3. Temperament, intervals and other musical compromises. Heavy going, please skip if desired.
What is temperament? It is the progression and timber that defines the music as heard by the human ear. There are many kinds of temperaments, and the Indian system and the western system are different from each other in their temperament and tuning, though the concepts of notes, scales and intervals are common.
Pythagoras found that the ear finds certain frequency ratios very appealing. The most appealing is 1:2 (the octave mentioned earlier), or double the frequency. The next most pleasing was the fifth (2:3) and then the 3rd (3:5). These intervals were known as 'Pythagorean' intervals, and for a long time were the defacto standard (and still are the basis) of most 'western' music.
When the piano was being designed initially, it was with the pythagorean system. But if you had an instrument which played in strict pythagorean intervals, you would not be able to play the same melody across different keys. This was limiting instruments like piano from becoming an ensemble instrument, as mentioned in the previous section. Music was moving from solo to multiple instruments, and composers needed to be able to write for multiple instruments across keys.
A bit of explanation here of range. Each musical instrument (including the human voice) has a bottom note and a top note beyond which it cannot comfortably reach - at the right volume and intonation. Construction of musical instruments dictates their 'range', so a cello and a violin reach different ranges of the spectrum. To enable ensembles to go beyond the limitations of the pythagorean system, a new system was needed.
Therefore, equal temperament tuning emerged. It is a tuning for fretted, wind and percussive instruments that divide the musical spectrum between octaves into equally compromised intervals, so that scales can be played in 'unison'. The old systems, because of their concentration on the absolute frequency, had some tonally perfect intervals and some horrible intervals to dump the frequency errors into (and therefore unusable).
Using this tuning system, we end up with 12 tones with equally spaced frequencies, with the 'tonal center' at A, or 440 Hz. Since the spacing is equal, starting from any tonal center would guarantee the same sound if the same intervals were used.
This is not the only way to divide the octave, though - There is a 43-step system in existence as well. Just that this system is the most modern one - and the only one on our guitars. A lot of people don't like the equal temperament system because some intervals sound odd.
4. Whew, so I still haven't learnt anything except history - where is this going?
Actually nowhere, so let's get going. I'll steamroller through here.
Remember we had put our finger on octaves, take it off. We divide the octave and end up with 12 notes from C to B, defined as C, C#, D, D#, E, F, F#, G, G#, A, A#, B. # denotes 'sharp'. Each interval is known as a semitone or half-step. When we get to C all the notes repeat again, and you get to the next octave. The A is 440Hz, which is obtained from a pitch pipe. There are no sharps between E and F, and between B and C.
This is not arbitary - the first scale was middle C, and the 'correct' intervals were defined on this basis, which led to the chopping of E#/Fb and B#/Cb. 'b' denotes a flat, because it sound like that when you play the note after the fundamental. All flats are 'enharmonic' (sound the same as) with the sharps. These are Db=C#, Eb=D#, Gb=F#, Ab=G#, Bb=A#.
In the piano all the notes are arranged in a line, with the sharps (flats) in the little black keys and the pure notes in the white keys. C major scale on the piano is simply all the white keys in a line.
Next instalment we will talk about intervals and the circle of fiths, and begin to apply these to our playing.
5. Practical application:
What you can do is learn your way around the fretboard.
Basically pick a note and play it on any string. So think of a note, and then play it on each of the 6 strings where it occurs. Ask a friend to call out the notes. Try and get the smallest time between your notes.
For example, call A, and play the high E string 5th fret, b string 10th fret, G 2nd fret...
You get the idea. This will also help when we get to chords two instalments later, and enable you to quickly pick up basic chords.
Use this image to help you at first:
http://img256.imageshack.us/img256/2572/fretboardmapgx0.gif
Guitarnoise is a great resource for lessons, do stop over there and have a look. I've learnt a lot of concepts and songs there, very good if you like folk and standards.
Try and not look at the image for at least some notes, wean yourself off them. If you're practising your scales, then call out the notes as you play them.
6. Bonus section: Tuning your guitar.
Every lesson has to give you something useful, so here it is:
A lot of people ask the question "How do I tune the guitar" and get all sort of answers. The truth is you can tune your guitar any way you want, but it may or may not sound good. It is possible to tune a guitar such that you can play a single pentatonic scale across the open strings, but it may be boring. OK for one song or two, but boring.
So a guitar is most commonly tuned in standard tuning, which is (starting from the thinnest string) e, b, G, D, A and E, with the heavier strings going lower in pitch. You can use a reference pitch from a piano, PC program, pitch pipe or tuning fork, for the note A. The best way to tune is to match the reference note to the same note on each string. This also will help you find your way around the fretboard quickly.
A good way to tune when you're just starting out, is to sing the reference note and the guitar note, to know whether it's high or low. When I started I was tone deaf (not that I've improved much) so I would find other ways to tune the guitar, mostly to my voice, and sometimes to harmonics. It would never play in tune with other instruments, but I found myself learning many songs quickly that way. I do not advise this, it's better to tune up to reference notes.
Once frequencies get close, you will be able to hear 'beats', or the differences between frequencies. It will pulse and the sound will sound like it's literally 'beating'. Once the beating stops, you're either dead tuned, or way too high or low. Use this aural trick to tune up quickly.
7. Further reading
If you want to get into temperaments and historical tunings in-depth, the wikipedia page on equal temperament has a decent explanation but the links are outstanding, do drop in and take a look. There's history, maths and music all together in it.
Equal temperament - Wikipedia, the free encyclopedia
8. Feedback and questions
Do let me know if there's something you felt was missing or unexplained and I'll try my best to answer. Also If I've made boo-boos, I would love to be corrected.
The part after this is pretty heavy, but I'll try and simplify it.
I sold most of my guitars when I moved to Bangalore... right now my main guitar is a Jackson, got an Aria Pro II recently for jazz/blues and still have an old Butterfly acoustic.
