View Full Version : What is three chord (C, F and G7)?

10-23-2016, 10:15 PM
Pythagoras found that simple 1/2, 1/3 or 3/4 length of string or weight of metal gives very good harmony with the original one. This is the origin of harmony in music, according to Howard Goodall. When we think C key (original) is, 1/2 is also C octave below. And 1/3 and 2/3 are G, 3/4 is F.

https://s21.postimg.org/aot8im88n/length.png (https://postimg.org/image/mqomcrhgz/)image post (https://postimage.org/)

This evidence is well described in this circle of 5th below. 2/3 of C string is G. 2/3 of G string is D.......

https://s21.postimg.org/3qlek9pxj/cirlce_of_fifths_sm1.gif (https://postimg.org/image/vqpi4jtdv/)free image hosting (https://postimage.org/)

F and G give best harmony with C. Hence we use them as member of three chord in key of C.

We can see 1/2 (C on the 3rd line), 3/4 (F) and 2/3 points (from saddle) on the fretboard.

https://s16.postimg.org/kpp2mfkg5/ukulele_fretboard_after.jpg (https://postimg.org/image/eordpcxtt/)image free hosting (https://postimage.org/)

Brad Bordessa
10-24-2016, 04:45 PM
Huh. Never thought of it like this.

10-25-2016, 01:56 AM
This beginner needs more explanation.

10-25-2016, 02:14 AM
I like the visuals here. Well done! :)

Thanks for sharing!

10-25-2016, 02:23 AM
There are 7 diatonic chords in the key of C

https://s9.postimg.org/71n1ie5vz/image.gif (https://postimg.org/image/3ushyrlfv/)upload photo (https://postimage.org/)

F and G harmonize with C most in the 7. Hence they are often used for framework of the song as three chord in the key of C.

10-25-2016, 12:20 PM
Now I get it, thanks.

10-25-2016, 11:32 PM
@Hippie Guy
I've just finished to read "Big Bangs: The Story of Five Discoveries that Changed Musical History" by Howard Goodall. It is very interesting book. I really did not know the meaning of circle of 5th ever before.

Thank you for asking. I've forgot to write most important thing. ^^

I always appreciate your posts including strings experiments.

10-26-2016, 02:56 AM
Impressive. I never thought about it in that way.