music theory general knowledge exchange

Hello fellow peoples. I'm a musician who loves to eat up any little bit of knowlege I can get from people who know more than me. I've got so many questions! For instance, what exactly is the definition of an arpeggio, or what exactly is dissonance, or what exactly is harmony between notes. We all 'sort of know' what these things mean, but I couldn't define it. This is intended as a thread for some of the more theory oriented people here to share some basic knowledge and enlighten the rest of us. I'll start us off- i'll explain the concept of modes. A mode is essentially a 'starting position' in a scale. Every scale has as many modes as it has notes in it. The major scale, having 7 notes, has 7 modes (ionian/major, dorian, phrygian, lydian, mixolydian, aeolian/minor, locrian) To utilize any of these modes, simply treat their coresponding 'starting positions' as the root of the scale. It's not difficult at all, they are all just versions of the same scale with an emphasis on different notes. If anyone would like further explanation, i'll be happy to explain! (I know a lot of you know this stuff already, but many of the musicians i've met did not. This is an opportunity for people to learn something useful =)

do you know about them? If so, do explain! I like to hear about these obscure musical things. Do you know about the medieval modes, or church modes? I've been wondering what those were...

I just know what I read here:

http://en.wikipedia.org/wiki/Pythagorean_tuning

It sounds interesting. 

An arpeggio is a chord played in horizontal (musical) space rather than vertical. In other words, it is the notes of a chord played one after the other, not at the same time. Since any combination of three or more notes is a chord, technically any melodic line could be called an arpeggio, but that's not what is usually meant.

Dissonance is an arbitrary concept that has changed throughout the years. It refers to the complexity of the waveforms of sound and how two or more pitches interact with each other. In Medieval times, anything other than a perfect fifth, perfect fourth, octave and unison was considered dissonant. As time went on, thirds and sixths became acceptable and today even major seconds sound fine to most of us.

Harmony between notes is basically the same thing. The frequencies of different pitches interfere with each other and we perceive this more complex sound as harmony. For example, A below middle C has a frequency of 440 hertz. The A above that is twice that frequency, 880 hertz. When two frequencies are combined, the ratio between them determines the harmony. A ratio of 2-1 as above is very simple and sounds as an octave, not really harmony. The E above middle C is approximately 660 hertz, and so has a ratio of 3-2 with the A below. This creates a perfect fifth. The more complex these ratios, the more "dissonant" the harmony.

The modes are divided into "major" or "minor" modes based on whether the third of the mode is major or minor. The major modes are Ionian, Lydian and Myxolydian, the minor modes are Dorian Aeolian, Phrygian and Locrian. As far as moods go, it's not really that simple. Phrygian has a "Spanish" feel to it and Lydian is enigmatic. I guess Mixolydian could be called "bluesy" but a lot depends on how they are played. The blues scale is not a mode, because it contains an entirely different set of intervals than the major scale. It is also only six notes, being 1-b3-4-#4-5-b7 of the key.

The Medieval modes are the same as the modes we have been talking about, except that they were further divdied up based on the highest and lowest note in the melody. For example, a medieval Dorian melody would have its highest and lowest note on or around D. One that used the same intervals but but had its highest and lowest note on or around A (the fifth) would be called Hypodorian.

EDIT: to correct factual errors.


Edited by thellama73 - June 20 2007 at 12:42

purplepiper wrote: lydian-major-melacholic/enigmatic/mysterious

THE_POLE wrote: Ok, so is there a scale/mode then that would allow me to write music wiith a european folky(scandinavian in particular) feel to it? I mean, it's easy to write blues melodies on a blues scale, but not knowing it it's a little more difficult because you have to work out yourself what intervals make a melody sound bluesy. Do folky melodies work in a similar way? What about middle eastern folk? I'm attempting to write music influenced by a lot of folk metal that i listen to, but i'm having trouble getting the melodies to sound right.

What is the utility when you play (for example), in dorian mode, major scale? You start by D, but, is there any utility? I never understood about it....Thanks for explanation

Edit: My teacher told to me, years ago, that the goal of "Modes" is to give another....."sensation". For example, in dorian mode, you will emphase on the D note and will add a certain....."feel" but I don't know how to get that feel, for me, it still a major scale...


Edited by Yann - June 21 2007 at 09:04

Yann wrote: What is the utility when you play (for example), in dorian mode, major scale? You start by D, but, is there any utility? I never understood about it....Thanks for explanation Edit: My teacher told to me, years ago, that the goal of "Modes" is to give another....."sensation". For example, in dorian mode, you will emphase on the D note and will add a certain....."feel" but I don't know how to get that feel, for me, it still a major scale...

Here's the secret man...every mode has one note that gives the mode its 'flavour'. That's the key to bringing out the modes character. Emphasise the roots, and the 'character note' as i'll call it. For example, the 6th note (if I recall correctly) is the character note in the dorian mode. You can also derive chords from this principle (which I came up with on my own!) some modes are more obvious in where their character lies, like the lydian mode, who's character note is the fourth note of the scale.

But how do you apply theses modes?