I started performing on the piano about 10 months ago. Of course, I don't play on an professional circuit, get paid, or anything like that. I only play for friends, fellow amateur musicians (www.amsf-perform.org) and people at retirement homes (younger people may know these as "old age homes"). Here are some of the things that a performer experiences.
The Nervous Beginning
For my first performance, I took up a very simple piece, so that I wouldn't have to worry about technical difficulties and could only focus on the performing aspect. Amongst a group of musicians ranging from beginners to amateurs, I was put last on the list to play. While some people played quite nicely, others seemed to struggle ("They should've practiced more" I felt). By the time I was to play, I was pretty much waiting for my turn. When my turn came, I eagerly went to the piano. When I sat to play, I suddenly found all kinds of things going on. My mind was in a swirl, my stomach had this funny feeling and my hands and legs were shaking. I was no way playing anything like what I had practiced. My mind wasn't working at all and I was just trying to get by. Now I understood where the "They should've practiced more" came from.
The event replayed itself in my mind a few times, and I was still wondering what happened. My piano teacher explained, "Expect to get nervous. Once you're nervous, then you can say, 'Okay, now I'm nervous. Here on, I can only try to do my best' and move on." The good part of nervousness is that it usually doesn't last forever. If you hang on for the first minute or so, your heart slows down, your mind gets calm and you get back into some sort of normalcy where you can "play" instead of "getting by".
Nervous also makes one start the piece faster than what one normally does. "This happens," as pianist Brian Ganz once explained in a masterclass "because the human metronome, the heart, is beating faster than normal". Starting faster when you're nervous is the sure recipe for disaster when your mind is in a swirl and your already shaking fingers can't keep up. Sometimes, in my eagerness to show my piano teacher a piece, I've done exactly that, ending up with my mind blank and finding myself in the middle of nowhere. So, now, I usually make a conscious effort to start slower, so that it is at the right tempo.
Expecting to be nervous has also made a lot of difference. I'm more prepared for the feeling instead of the "What is happening to me?" thing. I also try to make sure that I don't have any problem spots near the beginning
The Problem Of Trying Not To Make A Mistake
In my first performance, I was really trying my best to get everything right. It was a simple piece and I wasn't going to make a mistake. However, what ended up happening was that I was focussing on getting the notes right rather than playing the music. I probably lost out on some of the expression in the process. The beauty of music is in what you do right, not what you don't do wrong. In the end, people listening don't care about the mistakes you made. It is the musical content that matters.
In fact, trying to play perfectly has worked against me. It has taken the focus off normal playing and I've made mistakes where I normally wouldn't have. I remember some of the times I've played in front of my teacher. I'm playing a piece I've practiced a lot the past week and I want to show how well I play. A mistake comes in, makes me conscious, then another, and finally I'm forced to stop, take a deep breath and restart.
In recording, this is a dilemma. Mistakes in a recording really stand out because they grate each time I hear them. So, I'm left between simply playing and letting mistakes be, or trying to be more careful overall at the risk of other problems. Sometimes, I simplify some of the difficult spots, so that the chances of a sour note are low. But there seems to be no solution for it.
Trying To Keep Going
In conversation with my piano teacher, he told me an interesting fact. Pianists, even the best, always make mistakes. But, they just keep going as if nothing happened. Reminded me of a performance I attended. The young pianist, Naoko Takao, was performing wonderfully, when I suddenly heard a sour note. I knew the piece very well and so it kind of jarred me. However, she kept going, making me wonder if I heard it right, and then, at some point I moved on too. She finished the piece very well, and I felt that it was a perfect performance except for one note. Being an informal performance, I saw her talking to a friend as she walked out. She mentioned nothing about the note. Now, when I think of it, I realize that she had probably made several (most likely small) mistakes. What I had noticed wasn't anything out of the ordinary.
When practicing, I normally stop at a mistake to try and fix it before moving on. A piece doesn't feel right if a crucial note didn't sound. However, this is exactly the opposite to what one should do when performing. You can't undo or fix something that has happened. You have to keep going.
Often, particularly for difficult parts, I keep a "backup plan", where I know how to cover up, continue and move on, if I happen to make a mistake. Someone who doesn't know the piece wouldn't notice that something was amiss.
When performing, there are so many unexpected things when performing- "Why didn't that note sound?", "Shoot. I missed the B-flat", "That chord was completely wrong", "That key is out of tune". I keep trying to move on. Luckily, there is something called the auto-pilot mode to help.
The Auto-Pilot Mode
As you learn a piece and play it repeatedly, you develop a kind of muscle memory. This is similar to driving a car on a familiar route, when you can do everything perfectly, while your mind is in another world. While practicing a piece, I can be thinking of something else, like what happened in the lab or a conversation with a friend, while my fingers go on in an auto-pilot mode. The piece is usually quite bland and lifeless when played that way. Plus, it isn't 100% reliable. At the end of a phrase, it suddenly leaves me high and dry and I don't know what to play next. That's when I snap out of my mind wandering and try to get a bearing of where I am.
Nonetheless, auto-pilot mode has rescued me from so many lapses of concentration. I've made an unexpected mistake, and my mind is still in a spin about what went wrong. But my fingers do their job and I get the time to tell myself, "Relax. Keep going", and slowly get back into the piece. When auto-pilot mode fails during a performance, that is complete disaster. You have no idea where you are and your fingers don't know what to do next. You just have to stop, and then try to start somewhere. Hasn't happened to me yet.
The Gremlin
There is a phenomenon peculiar to performing, which my piano teacher refers to as the Gremlin. I'm playing fine, when suddenly a little Gremlin comes inside my head and asks, "Do you know what note you're going to play next on the left hand?". That's when, if I try to think of what I'm going to play on my left hand, I suddenly become conscious of it and what would have normally happened doesn't. Also, If I try to look at my left hand, I suddenly upset the hand-eye routine and make a mistake. The best response to the Gremlin, is to ignore it and get on to auto-pilot mode so that you're not conscious about what you're playing, and things happen as they are used to. The Gremlin visits me atleast once or twice during a performance. Thank God for the auto-pilot mode!
The Performance Piano
In one of my performances, the piano I was playing on just wasn't doing what I wanted it to do. I was playing exactly as I would at home, but the base was sounding over the treble. I tried to fix that by putting more sound in my right hand, made mistakes, gave up on that and then finished the piece, relying a lot on auto-pilot mode. All the carefully crafted expression just did not come out on the piano.
Practicing on a piano at home, I sometimes fine tune things so much that it ends up being very piano specific. It has taken a lot of awareness of the characteristics of my piano and gauging the performance piano to suitably adapt to it, as well as practice on a whole bunch of pianos so that my playing doesn't get very piano specific. I don't want any surprises while performing.
The Early Sigh of Relief
Often, after successfully getting through a particularly tough part, I feel "It's easy going from here. I just have to get through ....", when suddenly, having unconciously switched to auto-pilot mode, it fails me and I snap back with a jolt "It's not over yet", and I try to regain my concentration.
The End
Finally, when I play the last note, I tell myself, "You're done. You can't make a mistake from here". That is indeed a true sigh of relief. After releasing the last note, I look to see what the audience response is. Did they like it? Enthusiastic? Or was it just "some music" for them, which they didn't get? Often makes the case of what I choose to perform the next time.
Friday, March 20, 2009
Friday, March 13, 2009
Laser Cooling and the Anti-Murphy's Law
Laser Cooling follows some kind of Anti-Murphy's law. While normally, something you expect to work doesn't work as well. Like, a kilogram of petrol (or gasoline) in your car has 47 MJ of energy, it gives you less than 18 MJ to run your car. With laser cooling, things which were not expected to work have worked, while things which were expected to work have exceeded their limits.
One of the most fascinating stories I've heard from the history of laser cooling is that of sub-doppler cooling. It is one of the few times in science when experiments beat the theoretical limit.
A brief background of laser cooling. The idea came in the 1970s. For a gas of atoms, all the energy is in its motion. If you can slow the atoms down, their temperature will fall significantly. You do that by shining the proper laser light from the proper direction and using the photon momentum to slow the atoms down. Here is an instructive picture. In the quantum picture, light consists of miniscule, finite particles, called photons, which have a certain energy and momentum, like ordinary particles (for the record, photons differ from ordinary particles in that they have no mass and that they travel at the speed of light). Imagine a truck free-rolling (for eg. putting it on neutral gear at some speed) on a road. Now, if you stood in front of it and threw many balls (probably thousands) at it, it would slow down significantly. The atom is like the truck and the balls you throw are the photons.
What if the truck was moving away from you? If you threw balls at it, wouldn't it move faster? That's when the key concept of doppler shift comes in. When an atom is moving towards a laser beam, it sees the light at a higher frequency (referred to as blue-shifted. Blue light has a higher frequency than red light), the same effect as when you hear a train horn coming towards you at a higher pitch. Similarly, when an atom is moving away from a laser beam, it sees the light at a lower frequency (red-shifted), just like the train horn sounding at a lower pitch when the train has passed you and is moving away from you. The youtube video below is very instructive.
One of the key principles of quantum mechanics is discrete quantum energy states, which play a role when you consider tiny systems. If you consider an atom with 2 energy levels (simplest case; they typically have several), the atom can absorb (and later emit) light at a particular frequency which corresponds to the energy difference between the 2 states. It is referred to as a resonance, where atoms scatter light only if it is at the correct frequency. If you shone resonant laser light on an atom, it would see the light only if it was at rest. If you red-detuned (lowered the frequency) of the light, an atom moving towards the light would see it blue-shifted (increase the frequency). That would bring the light into resonance for that atom. The atom would scatter photons and be pushed back. An atom moving away would see the light red-shifted, which would move it further out of resonance. That atom will not be affected by that laser beam.
So, if you put "red-detuned" laser light from all directions, you'll get atoms trapped at the center. If any atom tries to move in any direction, it sees oncoming laser light on resonance, scatters photons and gets pushed back. One keeps a magnetic field gradient to enhance the effect of the laser beams (I'm skipping the details). This is called a Magneto-Optical Trap (MOT).
Below is a video of sodium atoms in a MOT. It is in a glass cell inside vacuum, so that other atoms and molecules, normally present in air do not destroy it. The bright spot you see is ball of trapped sodium atoms scattering the yellow laser light (same colour as sodium lamps) that is used to trap it. There are probably a billion atoms there.
Back to the story. Once the idea of laser cooling had been established, theorists (physicists who work on theory only) made a simple model for atoms and predicted that you could cool Sodium atoms down only to the doppler limit, 240 uK (microKelvin, 0.000240 degrees above absolute zero, much colder than liquid helium), which is the point at which the heating due to laser light prevents the atoms from getting colder. It was simple and straightforward enough and taken as the best you can possibly do.
When people started doing the experiment, they noticed something strange going on, where things were not behaving as expected. On taking a more careful look, they found out that the atoms were actually COLDER than the 240 uK! On playing around with the setup, they found they could cool the atoms down to 40 uK, 6 times colder than the doppler limit! To put this in perspective, the best solar cells have achieved 25% efficiency. Imagine if a scientist working on a solar cell found that she got more electrical energy from the cell than the total energy falling on it. That simply can't happen! So, how was it possible to beat the doppler limit?
It turned out that, in the simple model, the theorists had assumed a 2-level atom, which is quite reasonable considering that other levels don't participate in the cooling. However, it turned out that the other levels did in fact play a role and instead of preventing the atoms from being cooled to the theoretical limit, actually conspired to enable them to cool to a temperature 6 times lower! So, instead of being stopped at the doppler limit, we now have sub-doppler cooling and a sub-doppler limit.
Another story I've heard is from people who cool Erbium. Erbium is a more complicated atom with many more energy levels. The physicists had worked out the optimal parameters from theory and were making a MOT. They got some atoms trapped, and then decided to play around with the laser frequency. Trying out the laser frequency on the blue-detuned side of the resonance, they found that they were able to do better and got a bigger MOT. How is it possible that laser light which would push atoms away can even trap them? It turned out that the magnetic properties of Erbium played a role, and again conspired to make things work.
There are other such stories I've heard in laser cooling, where some kind of Anti-Murhpy's law seems to exist. While I'm sure that many people who work in the field face the usual frustrations and struggles of trying to make things work like they're expected to, it is amazing that there is are so many instances of Anti-Murphy's law where things have worked better than they should have.
One of the most fascinating stories I've heard from the history of laser cooling is that of sub-doppler cooling. It is one of the few times in science when experiments beat the theoretical limit.
A brief background of laser cooling. The idea came in the 1970s. For a gas of atoms, all the energy is in its motion. If you can slow the atoms down, their temperature will fall significantly. You do that by shining the proper laser light from the proper direction and using the photon momentum to slow the atoms down. Here is an instructive picture. In the quantum picture, light consists of miniscule, finite particles, called photons, which have a certain energy and momentum, like ordinary particles (for the record, photons differ from ordinary particles in that they have no mass and that they travel at the speed of light). Imagine a truck free-rolling (for eg. putting it on neutral gear at some speed) on a road. Now, if you stood in front of it and threw many balls (probably thousands) at it, it would slow down significantly. The atom is like the truck and the balls you throw are the photons.
What if the truck was moving away from you? If you threw balls at it, wouldn't it move faster? That's when the key concept of doppler shift comes in. When an atom is moving towards a laser beam, it sees the light at a higher frequency (referred to as blue-shifted. Blue light has a higher frequency than red light), the same effect as when you hear a train horn coming towards you at a higher pitch. Similarly, when an atom is moving away from a laser beam, it sees the light at a lower frequency (red-shifted), just like the train horn sounding at a lower pitch when the train has passed you and is moving away from you. The youtube video below is very instructive.
One of the key principles of quantum mechanics is discrete quantum energy states, which play a role when you consider tiny systems. If you consider an atom with 2 energy levels (simplest case; they typically have several), the atom can absorb (and later emit) light at a particular frequency which corresponds to the energy difference between the 2 states. It is referred to as a resonance, where atoms scatter light only if it is at the correct frequency. If you shone resonant laser light on an atom, it would see the light only if it was at rest. If you red-detuned (lowered the frequency) of the light, an atom moving towards the light would see it blue-shifted (increase the frequency). That would bring the light into resonance for that atom. The atom would scatter photons and be pushed back. An atom moving away would see the light red-shifted, which would move it further out of resonance. That atom will not be affected by that laser beam.
So, if you put "red-detuned" laser light from all directions, you'll get atoms trapped at the center. If any atom tries to move in any direction, it sees oncoming laser light on resonance, scatters photons and gets pushed back. One keeps a magnetic field gradient to enhance the effect of the laser beams (I'm skipping the details). This is called a Magneto-Optical Trap (MOT).
Below is a video of sodium atoms in a MOT. It is in a glass cell inside vacuum, so that other atoms and molecules, normally present in air do not destroy it. The bright spot you see is ball of trapped sodium atoms scattering the yellow laser light (same colour as sodium lamps) that is used to trap it. There are probably a billion atoms there.
Back to the story. Once the idea of laser cooling had been established, theorists (physicists who work on theory only) made a simple model for atoms and predicted that you could cool Sodium atoms down only to the doppler limit, 240 uK (microKelvin, 0.000240 degrees above absolute zero, much colder than liquid helium), which is the point at which the heating due to laser light prevents the atoms from getting colder. It was simple and straightforward enough and taken as the best you can possibly do.
When people started doing the experiment, they noticed something strange going on, where things were not behaving as expected. On taking a more careful look, they found out that the atoms were actually COLDER than the 240 uK! On playing around with the setup, they found they could cool the atoms down to 40 uK, 6 times colder than the doppler limit! To put this in perspective, the best solar cells have achieved 25% efficiency. Imagine if a scientist working on a solar cell found that she got more electrical energy from the cell than the total energy falling on it. That simply can't happen! So, how was it possible to beat the doppler limit?
It turned out that, in the simple model, the theorists had assumed a 2-level atom, which is quite reasonable considering that other levels don't participate in the cooling. However, it turned out that the other levels did in fact play a role and instead of preventing the atoms from being cooled to the theoretical limit, actually conspired to enable them to cool to a temperature 6 times lower! So, instead of being stopped at the doppler limit, we now have sub-doppler cooling and a sub-doppler limit.
Another story I've heard is from people who cool Erbium. Erbium is a more complicated atom with many more energy levels. The physicists had worked out the optimal parameters from theory and were making a MOT. They got some atoms trapped, and then decided to play around with the laser frequency. Trying out the laser frequency on the blue-detuned side of the resonance, they found that they were able to do better and got a bigger MOT. How is it possible that laser light which would push atoms away can even trap them? It turned out that the magnetic properties of Erbium played a role, and again conspired to make things work.
There are other such stories I've heard in laser cooling, where some kind of Anti-Murhpy's law seems to exist. While I'm sure that many people who work in the field face the usual frustrations and struggles of trying to make things work like they're expected to, it is amazing that there is are so many instances of Anti-Murphy's law where things have worked better than they should have.
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