The Wonder of One!

Yesterday David put me on the spot!  He asked how One becomes not two!  I asked him to give me a day to try and put into words something which is a feeling for One rather than a science.   I hope that putting it into words will turn the feeling into something understandable!

One boy

One and one and one and one makes 4 boys

David works with pianos, sound is his primary way of receiving information.  If David presses one note, it is just one, then he presses several, one after another and although he has used many notes you have made one piece of music.  Or you have one instrument playing solo, then the one is joined by several others and you have one group.  Within the one group there are several ones but they are now one group.  Or, two musicians play a duet together, it is one duet.  The thing itself is always One no matter how many components it has and each component is One.  The same with words, all made up from several letters but each letter has its own integrity.  One is wonderful is you start looking out for it, constantly changing and multiplying but always detectable in anything which is.
Here is a question, does One change?