HARMONICA

Harmonica may be of different make like Hohner, Suzuki, Seydel etc.

But they all have seven notes. When we play through each hole individually, the sound and pitch produced is different. However, they all can be harmonised and synchronised to produce wonderful music!
No individual hole (note) is great on its own.

Similarly we all have seven notes.

Body, Breath, Mind, memory, Intellect, Ego and Self. No one note is great or insignificant on its own.

Sometimes, we notice some missing notes here, bending and twisting of notes there. But they are to produce great music of different genre.

Q.E.D!