Quick and Dirty Basic Music Theory:
The Chromatic (all the notes) scale written twice: interval between adjacent notes is always a halftone (1/12th of an octave)
A A# B C D D# E F F# G G# A A# B C C# D D# E F F# G G# A
A#(A sharp) means 1/2 tone higher than A, and that is the same as same as Bb (B flat), which means 1/2tone lower than B. D# means same as Eb, etc, we will be skipping the b (flat)names for convenience.
Note that there is no # between B and C, or E and F. That is because those names are already a half tone apart (clumsy system, but it's what we've got.)
Diatonic Major Scale, any key; start from the ROOT note (root gives it's name to the key) and count half tones, collecting notes as you go, 2,2,1,2,2,2,1 (alternatively you could say "whole whole half, whole, whole, whole half").
From G (Root) that would give G, A B C D E F# G
From D ( a new Root) it would give D,E F# G A B C# D. Check my counting yourself!
Chords are groups of notes that sound good together.
To make a major chord: Write the scale for a given Root, then select the first note, the third note, and the fifth note (called 1,3,5) from that major scale. Root names the chord.
G major; G, A B C D E F# G (1, 3, 5 equals G, B, D)
D major; D, F#, A
What would a C major chord be? how about a F# major chord?
To make a minor chord: 1, 3flat (lowered by a halftone from the normal 3), 5. That makes:
Gminor (Gm) G, Bflat ( or A#), D
Dminor (Dm) 1, 3flat, 5
Seventh chord (easier to skip them and use major instead, but if you insist, 1,3,5,7flat... (should be called a flat seventh chord but it is not) G7 is G,B,D,F
Now, faster way to make chords, without writing major scale... just work from chromatic scale:
Major chord: Root, up 4 halftones, up 3 halftones (try it with G)
Minor Chord: Root, up 3 halftones, up 4 halftones (ahha!)
Seventh chord: Root, up 4, up 3, up 3 again.
Figure out the notes in the chord you need, look on the strumstick fingering chart, and do your best to finger it, if it is possible.
There are lots of chords you will never be able to get on a G strumstick, obviously, but if you can get two notes, you can IMPLY the chord.
As long as we have gone this far, lets add one more thing:
From any major scale (let's say G), give each note a roman numeral: G A B C D E F# G- I II III IV V VI VII Now, take:
the major chord built on I (G major),
the major chord built on IV (C major),
the minor chord built in VI ( Eminor), and,
the major (or seventh) chord built on V (Dmajor, or D7)
These are the most important chords in this key, the I, IV, V (orV7, to be really technical), and /or VI chords.......90% of songs use these chords in various combinations.
In key of C, they are C, F, G (or G7) and Am.....
these chords are in the same relationship to each other as G, C, D (or D7) and Em.
Note: we are not writing the word "major" anymore, but you should still say it.
A song that goes G, C, G, D (chords, remember) in key of "G" would also go C, F, C, G when transposed to key of "C" .
Strumstick®: Quick and Dirty Music Theory