It was the Scots air: 'Ca' the yowes to the knowes,' which was a favourite of my father's.
The whistler must have felt my presence, for the air suddenly stopped in the middle of a bar.

An unbounded curiosity seized me to know who the fellow could be.

So I started in and finished it myself.
There was silence for a second, and then the unknown began again and stopped.

Once more I chipped in and finished it.

Then it seemed to me that he was coming nearer.