102: How to play any simple music BETTER?

I remember in the beginning of my piano playing, I always wonder why although I'm playing the same chord as some pro people, but mine sounds so boring and theirs a pleasure to listen to. From my humble experience, there are 3 things that separate a beginner from a pro player.

1) Chords Variation

2) Rhythm

3) Melody line

For this post, we are going to learn about Chord Variation. 

Chord Variation

Now turn to your piano and play the following chord variation for C chord, and notice the added sound to the chord.

C = C,E,G
C7 = C,E,G,Bb
Cmaj7 = C,E,G,B
C6 = CEGA
C add9 = CEGCD (D is the 9th key of the c scale, thus called the C add9)
C9 = CEGBD (It's different from a C add9, it has a B in it and no high C)
C11 = CEGBDF ( If D is the 9th key, F would be the 11th)
C13 = CEGBDFA (A =13th)

Explanation
I can say in almost all situation, you can at least play any ordinary chord (ex. C chord) with the added 7(C7), in the case of the IV chord though, maj7 chords are much preferred.

In the key of C:

C7 = C,E,G,Bb 1,3,5,7b        // Sometimes, you can also play Cmaj7 C,E,G,B 1,3,5,7 

Dm7 = D,F,A,C 2,4,6,1

Em7 = E,G,B,D 3,5,7,2

Fmaj7 = F,A,C,E 4,6,1,3

G7 = G,B,D,F 5,7,2,4

Am7 = A,C,E,G 6,1,3,5

Experiment

Sample:

So if you have a song that goes like this:

C         *B/G         Am         G      F      G    C     C

London Bridge is falling down, falling down, falling down;

C         C         C               Dm    G      C

London Bridge is falling down, my fair lady.

With 7th chord:

You can play it with the added 7:

C         *B/G7          Am7   G7     Fmaj   G7   C        Cmaj7

London Bridge is falling down, falling down, falling down;

C         Cmaj         C7               Dm7   G7      C13

London Bridge is falling down, my fair lady.

*B/G means G chord with B as base, so: B,D,F,G 7,2,4,5

After that is master, substitute all of the 7 chord with the 9 chord:

Cadd9   *B/G7  Am9   Gadd9    Fadd9   Gadd9    C7       C9

London Bridge is falling down, falling down, falling down;

Cadd9   Cmaj         C7               Dm9   Gadd9     C13

London Bridge is falling down, my fair lady.

C9 = Cmaj7 +D

Cadd9 = CEG + D

Gadd9 = GBD + A

C13 = Cmaj7 + Dm on top C,E,G,B+(D,F,A)

Am9 = Am7+B (A,C,E,G + B)

Dm9 = Dm7 + E (D,F,A,C+E)

In a nutshell!

1) Begin a song with and add9 ALWAYS sounds good! (C > Cadd9), You can always open a song with a maj7 chord as well if you want it a little moody (C > Cmaj7)

2) Turn all the F > Fmaj7 or F9;  G> G7or Gadd9

3) give 7th or 9th to all minor chords: Am7, Em9, etc. 

4) End with Cmaj7, C9, C11, C13 for a special effect!