Okay kiddo, let's talk about barbershop music and seventh chords. Remember how we sing "Row, Row, Row Your Boat" together? Well, in barbershop music, people sing together in a group and harmonize.
Now, when they harmonize, they like to use a special type of chord called a seventh chord. This chord has four notes played together and they create a special sound that makes people feel happy and excited.
The reason it's called a "barbershop" seventh chord is because this type of chord was really popular in the old days when men would go to the barbershop to get their haircuts. The barbershop was a place where people would sing together and have fun.
So, when people sing barbershop music and they hit a seventh chord, it gives them that extra bit of excitement and happiness. It's kind of like when you eat your favorite candy and it makes you feel really happy inside.
And that's it, kiddo! That's all there is to know about barbershop seventh chords. They're just a really special type of chord that makes people feel happy and excited when they hear them.