The great thing about this activity is that this just goes out with the rest of his toys for a few weeks. We have one bottle with leaves, one with dried pumpkin seeds and one with acorns (which he likes to chew on she good thing they are contained).
They were sitting on the table and he spied them at lunch time (yes we are still in our PJs at lunch). I handed them to him one at a time so he could get the feel for them individually. He would shake one, then another, then try to grab the third. I helped him out and would man the third.
He immediately understood that they each made a different sound and felt different. Then we started making music with them. Once he was done with lunch, he kicked them around the kitchen.
We will definitely be doing this for other seasons and just some basic ones during the boring parts of the year.