Re-use your bottles

'Empty vessels make most noise' is a phrase I remember from childhood, along with 'Use your initiative.' I seem to remember that if I did use my initiative the words 'You thought? You THOUGHT?!' came my way soon after.

But today's post is not about my happy reminiscences but about sound - the science of sound. By the end of the seasonal festivities, if indeed you haven't already, you should find yourself with easy access to numerous empty bottles of varying sizes. You may already be able to play a bottle by blowing across the top, aiming a jet of air at the opposite section of the rim. If not, perhaps you can persuade someone to teach you.

Now if you sound a plastic bottle in this way, and then a glass bottle of the same capacity, will the pitch be the same?

Are bottles of greater volume pitched higher or lower than those of smaller volume?

Do all glass bottles of the same capacity have the same pitch? Will shape or thickness of glass make a difference?

Never again be a wallflower at a party! The cool folk may steer a wide berth but you're never alone with a bottle.

Twang on a can

Here, as unwisely promised yesterday, is a clip of me twanging the ring-pull of an aluminium fizzy drink can whilst simultaneously filling it with water. What do you think happens to the pitch of the note?

My own, subjective and non-scientific, opinion is that the pitch stays the same. The note seems to get higher because the upper harmonic partials are increasingly favoured as the can fills. If I were to blow the can like a flute then I would hear the air inside vibrating. Less volume of air, as the water replaces it, means a gradual rise in pitch. When I twang the can it is the can I hear resonating. The water dampens (no pun intended - 'deadens' might be a better word) the sound of the lower partials.

Today I went for a long walk by the sea so no sonic experiments. But tomorrow I shall continue to explore the seasonal debris and make some more rubbish instruments. If you would like to join in then hang on to all sizes of bottles, both glass and plastic, tin cans of various types, wrapping paper and anything else you think might produce a noise.

These instruments are rubbish

Before you consign the debris from your seasonal festivities to landfill and the recycling banks why not have some fun with it first? That is certainly my own intention and I'm starting with some fizzy drinks cans. I had a grand plan which I'll reveal tomorrow but on the way I noticed a thing or two. You may know that all plastic bottles of the same size play the same note if blown like a flute. Well aluminium cans are the same although it is not nearly as easy to produce a sound in this way. However, when you twang the ring-pull (which remains attached to the modern can after opening) the pitch varies betrween cans. Of the five cans I tried the pitch varied between G and Bb. These cans were all the same brand from the same multipack. Although the cans all contain the same volume of air there must be other variations in their construction.

The next thing I did was to twang the ring-pull as I gradually filled a can with water. It requires a steady hand. (Using a funnel has a deadening effect.) Why not try this now? I'll post a movie of my own experiment tomorrow. Before you begin, though, what do think will happen to the sound as you pour in the water? Does experience tally with your prediction?

Busking in Norwich part two

Here's the second show, again just under 15 minutes long. The emphasis is on the less professional, and occasionally crazier, kind of busker.

The guys in the picture aren't featured. I saw them this afternoon kicking up a storm with a kind of East European gypsy take on some well known tunes. They were certainly jolly and had tremendous stamina but their case was far from overflowing with cash when I looked. A pity - they deserved better.

Carol Singing

I do enjoy carol singing and last night was perfect for it - thick snow on the ground that was still white after two days lying on city streets. On the street I moved from earlier in the year there is a tradition of singing a few verses at each door and collecting for charity. Everyone who opens their door is treated to a verse of 'We Wish You A Merry Christmas' at the end. It takes perhaps an hour to visit all the houses and then we retire to one of them for mince pies and mulled wine to warm the extremities. One thing I love about singing carols is the sense of a shared culture. The older folk knew the words to at least the first verse of most of them and the value of all those turgid school assemblies and enforced church attendance becomes clear.

The other evening as I was about to leave the house I heard a knock at the door. I opened it to a boy of about ten or twelve. He sang:
"We wish you a Merry Christmas
We wish you a Merry Christmas
We wish you a Merry Christmas and a Happy New Year"
and then stopped. It was all he knew.

It felt more like trick-or-treat than caroling but I didn't want to discourage him from singing and appreciated his courage.
'I'm going away for Christmas,' he said.
'Good for you,' I replied.
I gave him 50 pence (I didn't want to give him too much incentive to return!) and then noticed his friend overlapping him as they worked their way down the street. Very time-efficient; these boys will go far!

I thought of putting a notice on the door along the lines of "No Carol Singers UNLESS you know the first verse of at least TWO carols by heart". But of course I didn't. And tonight the folk on my new street are going caroling. The snow looks like sticking around so bring it on.

Busking in Norwich part one

Shortly before Christmas 2005 my friend Eamonn Burgess went out with a hand-held audio recorder interviewing buskers on the streets of Norwich. From the material he gathered we made two short (just under 15 minutes) radio programmes that were broadcast on Future Radio the following spring.

If ever you've busked, considered busking or even casually wondered what it's like for the person behind the guitar (saxophone, tambourine or whatever) then this is for you. It really is most illuminating and very entertaining, although not always for the reasons intended by the featured performers.

Unlike some towns and cities Norwich has a very relaxed attitude towards buskers. There is no police harassment and the council doesn't exercise any 'quality control' making for varied fare. However, the arrival of privately owned 'public' spaces such as Millennium Plain and that bit outside the new mall has altered the lay of the land somewhat.

Part two to follow.

How very sweet

As a woodwind teacher I have found myself occupying a unique position in the lives of some of my younger students. I am that rare thing: an adult they come to know well who is neither a family member nor a school teacher. ( Although I teach in schools it quickly becomes clear to them that I am not gunning enthusiastically for the establishment.) Perhaps if I taught something else - guitar or literacy perhaps - the same relationship would arise. But reed instruments require an embouchure and an embouchure requires practice. Kids who don't practise can't play solidly for a full lesson so I have learned to break up the playing in various ways. I have also learned that children come to their lessons for reasons other than music. Some really need to talk to a neutral adult without incurring the stigma, and parental worry, that asking for counselling would entail.

So I can talk knowledgably about nail varnish, ties and trainers along with the barriers they present to learning. And other things. It may not be necessary to build a friendly relationship with a student in order to impart knowledge but that's my style.

Today a boy came in wearing jeans and a t-shirt. Normally he would be wearing a uniform. I asked him if it was a non-uniform day.
"Yes. I just had to bring in a bag of sugar."
"A bag of sugar?" I repeated.
"Yeah. It's for the homeless in London or something."

I quipped that next year he'd have to bring in a tube of toothpaste but it did make me wonder. It also reminded me of eating white bread, margarine and white sugar sandwiches at school because it was all I could get my hands on. I can still remember the satisfying crunch that made me feel I was eating something substantial and sustaining. My teeth have been full of metal ever since. So what is the sugar for? Will it really be fed to the homeless or is it to be exchanged for something else, like the milk-bottle tops we used to collect for the blind? How can I possibly teach while I'm worrying about this? Would I have made more money in dentistry? Well, obviously.

Next time I might just keep my keep my curiosity in check. After all, my students talk about all sorts of things but never my attire. So why should I mention theirs?