intervals

Theory 101: Building Piano Chords

by David D. on March 28, 2010

Here’s Nate again, this time with a lesson on building chords in the key of G Major.  From the last lesson on scales and the circle of fifths, you’ll remember that the key of G Major has one sharp: F#.  So the scale runs as follows: G-A-B-C-D-E-F#-G.

The most basic chord is a triad, which consists of three notes stacked in thirds.  To build a Major chord, start with a major 3rd, then stack a minor third on top.  The G Major chord is a triad consisting of notes G, B, and D.  G to B is a major 3rd, and B to D is a minor 3rd.  In the lesson you’ll see that you can build chords by playing every other note in a scale.

Moving up a whole step and playing A, C, and E simultaneously produces an A minor chord. As you approach the top of the scale, extend it another octave to fill out the chords. For example, to form a D Major chord, you would press D (skip E), F# (skip G), and A.

Now for the good stuff. Take what you learned and move it down to C. Starting with notes 1, 3, and 5 (C-E-G), move the shape up the keyboard until you reach the C Major chord one octave higher. By playing every other note on just the white keys, you will play the following chord progression: C Major, D minor, E minor, F Major, G Major, A minor, and B diminished.

This progression of Major, minor, and diminished chords is the same for every major scale. The chords are often referred to by their position in the scale, and indicated by the corresponding Roman numeral.

Chord Symbols, Chords, Scale Degrees, Notes and Intervals in the Key of C Major

Roman numeral I ii iii IV V vi vii°
Chords C D minor E minor F G A minor B dim
Scale degrees
tonic supertonic mediant subdominant dominant submediant leading tone
Scale Notes
C D E F G A B
Interval from C
Perfect
unison
Major
2nd
Major
3rd
Perfect
4th
Perfect
5th
Major
6th
Major
7th

Harmony in Western music relies mainly on the primary triads: those built on the tonic (I), subdominant (VI), and dominant (V) scale degrees noted above.  The chords themselves are often referred to by the Roman numerals I, IV, and V, which in the key of C would be C Major, F Major, and G Major.

While it’s not important to immediately memorize all of the names and nuances of notation, it is critical to understand the relationships between keys, chords, and scale degrees.  Just knowing I, IV, V will take you a long way, since most popluar music is based on these three chords, sometimes with one or two others mixed in.  Once you are comfortable building chords in common keys, it’s time to move on to chord progressions.

{ 3 comments }

Theory 101: Basic Intervals

by David D. on February 22, 2010

Type “music intervals” into Google and you get over 5 million results, most of them useless.  They are either too long or too complicated or of poor quality or just plain wrong.  The best introduction to intervals I found was at pianolessons.com.  The YouTube video is below, or you can see the video along with a transcript here.

Basic Intervals

Missing from the presentation are examples of the intervals as used in well known songs.  If you are serious about your musical studies, these are important – they may be the only way (besides cheating) to pass an ear-training course.  Think of these songs as Nate plays the intervals, then go to the keyboard and play them yourself.  I have included the notes for each interval, using middle C as the starting note.

Interval Song References
minor second: C to Db Jaws theme, “I’m Dreaming Of A” White Christmas
major second: C to D Frere Jacque, Happy Birthday
minor third: C to Eb Rock A Bye Baby, To Dream The Impossible Dream
major third: C to E Oh When the Saints, Morning Has Broken, verse and guitar riff of “Blister in the Sun”
perfect fourth: C to F Auld Lang Syne, Here Comes the Bride, Hi Ho
Tritone: C to F# The Simpsons theme, Maria (West Side Story)
perfect fifth: C to G Twinkle Twinkle Little Star, Star Wars (Main Theme), Sprach Zarathustra (2001 Space Odyssey)
minor sixth: C to Ab The Entertainer (notes 3 and 4)
major sixth: C to A My Bonny Lies Over The Ocean, NBC theme
minor seventh: C to Bb Star Trek Theme, Mirage
major seventh: C to B Bali-Hai (1st and 3rd note) or Scary “Woo-hoo!”
perfect octave: C to C Over the Rainbow

[The minor sixth and major seventh are tough -- let me know if you have better or more up-to-date examples. Not sure how may kids out there are down with Bali Hai.]

Start with the major and perfect intervals (the white keys above C).  Once you are comfortable with them, move on to the next two lessons:

Intervals & Octaves Part 1

Intervals & Octaves Part 2

So now we know that intervals are just the spaces between notes.  If you absolutely must know the mathematical relationship between the notes, and have always wondered what A 440 really means, the answers are revealed here.

{ 1 comment }