Are you as in love with the number seven as I am? There is just something intriguing about the number.
I always wanted to open a cafe and call it "Cafe Seven". I don't know why. Then I started finding 'sevens' everywhere.
Of course we know that God made the earth in six days, and rested on the seventh- creation=seven.
In the Book of Revelation there are seven churches, seven spirits, He holds seven stars, the seven seals, the seven trumpets, and so on. Seven is used over 700 times in the Bible. It is used 54 times in the Book of Revelation alone! (more on that here) But seven in music? YES.
Take a look at a piano keyboard. The first white key is the "C". This is the grounding for where form begins when positioning your hands on a keyboard. Your right thumb on the "C". If you count the white keys from "C" to "C" you get seven. There are seven white keys in an octave. There are also seven FULL octaves in a Full Size 88-key Keyboard!
When forming a Major Chord, place your thumb on the middle "C". Using your index finger, count (on the black and white keys) 1-2-3-4 then stop and let your index finger rest there. Then continue with your pinky, 5-6-7, and let your pinky rest there. You have a Major "C" Chord.
4+3 = 7. Every major chord = 7.
Do the exact same thing again, except rest the thumb on the "C" and count 1-2-3, then 4-5-6-7, and you have a C minor. 3+4 =7. Every minor chord = 7.
Isn't that fun?! God is so amazing!