Carnatic Music vs Hindustani Music vs Other forms

I simply couldn’t resist penning down my views on this subject after reading Smt. Lakshmi Sriram’s article in The Hindu (Chennai):
http://www.hindu.com/ms/2007/12/01/stories/2007120150210600.htm

I must admit that I am hardly familiar with forms of music other than Carnatic (and maybe to some extent Western Classical). However, I have attended a Hindustani concert or two, and I hope I do make sense when I talk about Hindustani music or other forms. Please correct me if I’m wrong. Of course, this post might be highly biased, but that is natural because it’s a personal opinion – take it or chuck it!

While not purely so, most forms of music have some aspect that results in ‘intellectual enjoyment’. One must be able to understand the nuances of the music to wholly appreciate it.

In my opinion, the ingredient of music that requires the least amount of musical training to appreciate is simple rhythm patterns. Somehow, I’m inclined to believe that this is why the likes of Shivamani are extremely popular – because they come up with simple, but yet innovative, rhythm patterns which the common man can understand and appreciate. The other ingredient is Lyrics, preferably in English. I attribute the popularity of those forms of “music” that I would love to derogate by branding them as ‘noise’ to the fact that they are rhythm-intensive or Lyrics-intensive, and thus understandable by most people.

Then there’s harmony. I found out from my friend that not everyone can actually appreciate harmony. Western music primarily relies on harmony. Western Classical music utilizes ensembles of instruments to produce harmonious tones. Other ingredients like the tonal content or rAga, are harder to pick up unless one is trained in the particular form of music.

Carnatic music involves not only a lot of rhythmic complexity (eg: Pallavis, or stuff played in a taniyAvartanam) that is hardly understandable to the untrained ear, but also a lot of tonal complexity (heavy bhRgas and gamakams) that requires a really fast ‘Fourier Transform’ in your brain! What is suprising is that training can make the brain capable of ‘parsing’ every single note in a tonally complex phrase of music.

While Hindustani music might be tonally complex, it is mostly mellifluous and doesn’t involve as much rhythmic complexity (unless I’m mistaken) as Carnatic Music. Carnatic music is sharp, whereas Hindustani is mellifluous; and unless your ‘Fourier Transform’ is fast enough, you can’t appreciate T N Sheshagopalan’s 3rd kAlam swaras in the Alapanai (I still can’t!), which will just sound like drab nonsensical oscillations with no tonal beauty, explaining the popular impression of Carnatic Music. Hindustani Music, especially when rendered popularly, on the other hand, doesn’t require as fast a Fourier Transform – except for some parts of the concert. Thankfully, Hindustani music has these slow phrases which the untrained ear can appreciate, making it more popular.

So I would conclude that the popularity of non-classical forms of music, and above that, that of Hindustani over Carnatic is mostly because Classical Music, and in particular, Carnatic Music doesn’t pander to the average unacquainted man but offers a steep learning curve and calls for appreciation at various levels – emotional and intellectual.

Artifical real-time reverb using sox

I had to dig through several pages of tweets to find this command:

sox -d -d reverb 80

It basically feeds back from the mic to the speaker with the reverb effect. So if you like a lot of reverb while playing a musical instrument, for instance, but your room doesn’t have the reverb, then you could run this to get the required reverb.

I’m putting this down here, so that I can search for it the next time I want it

There are other methods, like:

rec -t wav – | play -t wav – reverb 80

But that requires a lot of processing time, so there’s a significant delay between the input and the output…

A python IRC bot for keeping up with arXiv (or any RSS feed)

After some internet searching, it wasn’t hard to find enough inputs to write a IRC bot using Python. I hardly know any Python, but the language being so simple, you could write code in it just right away. Needless to say, the best part was that there were libraries for both Feed Parsing (duh!) and for IRC clients. A simple one hour long digging through documentation resulted in the following put-them-together code:


#!/usr/bin/python
#
# IRC b0t that keeps track of RSS feeds
#
# Licensed under the GNU General Public License v3
#
# Copyright (2009) by Akarsh Simha

import irclib
import feedparser
import os
import threading
import time

channel_list = [] # Put in a list of channels
feed_list = [ "http://arxiv.org/rss/hep-th", "http://arxiv.org/rss/cs", "http://arxiv.org/rss/math-ph", "http://rss.slashdot.org/Slashdot/slashdot"]
old_entries_file = os.environ.get("HOME") + "/.b0t/old-feed-entries"

irc = irclib.IRC()
server = irc.server()

server.connect( "irc.freenode.org", 6667, "" ) # TODO: Make this general
# server.privmsg( "NickServ", "identify " )

msgqueue = []

def feed_refresh():
FILE = open( old_entries_file, "r" )
filetext = FILE.read()
FILE.close()
for feed in feed_list:
NextFeed = False
d = feedparser.parse( feed )
for entry in d.entries:
if entry.title in filetext:
NextFeed = True
else:
FILE = open( old_entries_file, "a" )
FILE.write( entry.title + "\n" )
FILE.close()
msgqueue.append( entry.title + " : " + entry.link )
if NextFeed:
break;
t = threading.Timer( 900.0, feed_refresh ) # TODO: make this static
t.start()

for channel in channel_list:
server.join( channel )

feed_refresh()

while 1:
while len(msgqueue) > 0:
msg = msgqueue.pop()
for channel in channel_list:
server.privmsg( channel, msg )
time.sleep(1) # TODO: Fix bad code
irc.process_once()
time.sleep(1) # So that we don't hog the CPU!


Forgive me for writing ugly code. I’m a newbie pythoner, and this is my first python script that actually does something useful.

On a side note, I attended a semi-classical concert by Anil Srinivasan (Piano), Unnikrishnan (Vocal), and B S Purushottaman (Kanjira), and it was one awesome experience. The auditorium (the Lady Andal School auditorium, where Margazhi Raagam was shot AFAIK) was simply superb. The ambience, and the stage lighting were amazing too. It was the confluence of the music of all three artistes, the auditorium and the lighting that created the paradise that we experienced.

Dibrugarh photos uploaded!

Snow-capped-peak-2, originally uploaded by Akarsh Simha.

Photos of my trip to Dibrugarh are finally up, after I’ve overcome eclipse-depression. A few processed ones are on my Flickr Album at http://www.flickr.com/photos/asimha while the bulk, raw photos are on my Picasa Album at http://picasaweb.google.com/akarshsimha

A terribly disappointing TSE2009

This trip to Dibrugarh was the most miseventful and depressing trip so far in my life, IMO. Never have I felt so disappointed before. Dibrugarh neither turned out to have a good lot of scenic travel options around, nor did we get to see the eclipse of the century – the 3.5 minute totality predicted at Dibrugarh. All we got to see was the Brahmaputra, and the darkening of the cloudy, overcast skies during the totality (and the random behaviour of birds).

The only “perks” of the trip were insignificantly few – that of having a brief look at Kolkata, some good photographs involving dragon flies, the Brahmaputra, spiders and tea plantations, and some time spent away from the computer, with friends. Not enough and not worth it – just like several of those recent Hosahalli trips under overcast skies.

Besides, I hate travelling without good company – sitting doing nothing in the flight, for example. All I can do is to crib and compose this post, so that I can vent out some frustration of an untriumphant waste of a journey at the least, and ease myself a bit.

Over all, it was really disappointing to go all the way for absolutely nothing. This was much worse than that pathetic, most pointless visit to Kavalur that happened last year around the same time (which I did not blog about), which was much better in that I did not miss any significant event. These are the times when you start becoming agnostic… Wish I were in Varanasi with Amar and Vivek instead.

I amn’t alone – all of us were really disappointed. Particularly the two Pavans who calculatedly (and I say their arguments were logical!) changed the venue from Varanasi, which we had initially planned, to Dibrugarh. I don’t blame them for anything, because their reasons to favour Dibrugarh were absolutely sensible. Many folks pointed out that Dibrugarh was at a cloud-cover maximum as per predictions, but then Patna, which was at a predicted=cloud-cover minimum, had only overcast skies. It’s just our bad lack… really bad luck.

I guess I will be making a lot of trips to Argentina just to compensate… at the least I will end up visiting and exploring a foreign country instead of a boring, hot, and monotonously Indian town.

I’m currently at an enthusiasm minimum, so don’t expect any trip photos in the near future.

A summer at TIFR

As you all know if you’ve been reading my blog, I spent my summer at the Tata Institute of Fundamental Research (TIFR) at Mumbai, as a visiting student under their Visiting Students’ Research Programme (VSRP).

I’m now back to Bangalore, with lots of time to spend blogging the proceedings of the last one month.

I somehow felt I didn’t do much work during the last one month. I computed the Jacobian of the operator that I talked about in my earlier post, and it turned out to be unity for all that hard work . But well, it was a good thing it was unity because it didn’t complicate the equations all the more! So we were able to write down the kernel for the Navier-Stokes equation. Then came the task of converting symmetries into constraints on the two-point correlation functions of the velocity field. I wrote down Ward identities, but I couldn’t solve them. Prof. Spenta gave me an ansatz to try and I didn’t have much luck with it. That apart, we ran into some interesting issues regarding anamolous scaling dimensions, which still need resolution.

But here I’m, back in Bangalore, hardly spending time on Physics. It’s just that I’m lazy to start…

Overall, I must rate VSRP as a good experience. My sleep requirement seems to have reduced drastically and I sleep deeper these days, thanks to the fact that we were baccommodated off-campus at Wadala (1 hour away from TIFR / Colaba) – which was, according to me, one of the major downsides of VSRP. The other downside, IMO, is that TIFR is a research institute, and professors don’t know what to expect from undergrad students. However, in my case, Prof. Spenta very quickly adapted to my ignorance and I patiently taught me fundamental concepts! But then, it is good exposure to the scientific community.

Life in TIFR is really comfortable. The west canteen’s awesome food is pretty well-known. Plus, work timings are very free. There are colloquia every now and then and it is really interesting to see biologists attending Physics seminars and vice versa – promoting interdisciplinary exchange of ideas. I think TIFR is the place to be in India for research, and VSRP is an ideal summer internship programme.

I’m a fresher joining IITM – Should I bring a laptop?

This blog post might have some use for freshers who have the aforementioned question in mind – to bring or not to bring a laptop in the first semester. This was a reply that I sent to a student’s parent, and thought it might be useful to others. This post will expose the pros and cons of having a laptop, but will leave the ultimate decision to you. As a side note, in my case, I took my desktop in the first semester because I was (and still am trying not to be) a computer “addict” (thankfully, in a better sense than a game addict). This post might have a bias towards physics department students once in a way. So here goes.

Pros of bringing a laptop / buying a desktop:

All students will do a course on Computational Methods in their first or second semester. The Engineering Physics students will probably do it in the second semester, whereas the dual degree MS in Physics students will do this in the first semester. A laptop is useful for this, as you might have assignments where you will need to write and submit a program.

Although there are places to access a shared computer (which I will outline later), you will not enjoy the comfort of your room while studying / working. So it’s a good idea to have a computer in your room.

Much of the teaching in the first few semesters is done via computer-based presentations (commonly dubbed “power-point”) rather than on blackboard, so a personal laptop / desktop computer will be useful to study for the examinations.

I’m a fresher joining IITM – Should I bring a laptop?

This blog post might have some use for freshers who have the aforementioned question in mind – to bring or not to bring a laptop in the first semester. This was a reply that I sent to a student’s parent, and thought it might be useful to others. This post will expose the pros and cons of having a laptop, but will leave the ultimate decision to you. As a side note, in my case, I took my desktop in the first semester because I was (and still am trying not to be) a computer “addict” (thankfully, in a better sense than a game addict). This post might have a bias towards physics department students once in a way. So here goes.

Pros of bringing a laptop / buying a desktop:

• All students will do a course on Computational Methods in their first or second semester. The Engineering Physics students will probably do it in the second semester, whereas the dual degree MS in Physics students will do this in the first semester. A laptop is useful for this, as you might have assignments where you will need to write and submit a program.
• Although there are places to access a shared computer (which I will outline later), you will not enjoy the comfort of your room while studying / working. So it’s a good idea to have a computer in your room.
• Much of the teaching in the first few semesters is done via computer-based presentations (commonly dubbed “power-point”) rather than on blackboard, so a personal laptop / desktop computer will be useful to study for the examinations.
• From the second semester onwards, internet / intranet connectivity will be provided in hostel rooms for restricted timings. Thus, personal laptops / computers will be useful from the second semester onwards, since it will make it easy to communicate or get information.

Disadvantages of bringing a laptop / buying a desktop in the first year:

• The internet facility is not provided during the first semester in the hostels
• There are some very good common computer facilities, particularly if you are a Physics student. The Physics dept. computing facility is a really well-maintained facility that is almost always accessible. A list of other common places to access a computer figures at the end.
• Most students bring a desktop / laptop only in their second year. Thus, any laptop / desktop available in the wing will be in high-demand by your wingmates! Sometimes, this can get irritating – but it isn’t a serious problem if you don’t mind helping your wing-mates. I remember that although I used to try to be liberal with my desktop, it sometimes used to get me frustrated when I find it booted back into Winblows from Linux. I remember that I formatted the Winblows disk some day suddenly in frustration.
• It’s a good thing to avoid internet / game addiction and explore exciting hobbies that you can pursue in the institute in the first year. Internet can be addictive if you are seeing it for the first time at IITM. If you’ve already been a heavy internet user – then this point doesn’t concern you, as you’ve probably outgrown the initial hype now.

Places where you can access a computer:

• The Hostel Computer Room: This is a common computer room in the hostels. Usually, it is badly maintained – but then, there’s an administrator whom you can “pain” and get stuff working if it isn’t. This is the nearest computer-place near your room. However, by Murphy’s Law, all the computers here are occupied when you most need them – so it is better to know other alternatives!
• A Senior’s Room: Most seniors understand how important internet / a computer is for your survival (at least I do!) and will let you use their computer after you are subject to some basic “interaction”. I remember that a very friendly 4th year made a very open offer for us to use his computer whenever we wanted, and we actually used it for preparing some presentation.
• The Department Computing Facility: This is a facility that exists (well, rather is supposed to exist) in every department. Although I do not know, I’ve heard cribs that these aren’t well maintained in most of the departments. However, the Physics and Computer Science departments have very well maintained DCFs that are open for most of the time when one is awake. The administrators are very approachable too. This will be about 8 ~ 10 minutes on cycle from your hostel
• The Digital Knowledge Center: This is a place in the library which is typically crowded and has no place left for you to access a computer . It has mostly Winblows machines, which is why I’ve never been there after my first semester. If you do have a laptop, you have WiFi connectivity in the library, and the DKC has reasonable signal strengths as well. There are some Linux machines, but they are probably servers. The DKC will also be about 8 ~ 10 minutes on cycle from your hostel.

And a final point: Don’t get too worried. Things will be fine.

Metric Tensor

After a discussion with Henry de Valence (hdevalence) on IRC, who wanted to know something about the metric tensor, I thought I should put down some stuff that I explained to him. This is like a “Why a metric tensor” article.

A quadratic form, is a homogeneous polynomial of degree 2, like

We can always represent such a polynomial of degree 2 by a symmetric matrix:

[x y][1 1][x]
     [1 1][y]

[I'm sorry, I still don't know how to type matrices in LaTeX, and I want to put-off learning that for a later time]

So, let’s try to represent the distance between two points, which is a quadratic form, as a matrix. Let’s consider very small distances – between two closely separated points: (x, y, z) and (x + dx, y + dy, z + dz) where dx, dy and dz are “very small” distances.

Ordinary 3-D “Euclidian” Space, Pythagoras theorem reads:


[dx  dy  dz][1 0 0][ dx ]
            [0 1 0][ dy ]
            [0 0 1][ dz ]


Special relativity tells us that time is just like a “coordinate” and we shouldn’t treat it separately. Space and time are now put together and called “space-time” and there are 4 coordinates. The “distance” (Space-Time interval) between two points (t, x, y, z) and (t + dt, x + dx, y + dy, z + dz) is defined like this:


[dt dx dy dz][ -c^2           ][ dt ]
             [       1        ][ dx ]
             [           1    ][ dy ]
             [              1 ][ dz ]


Just like distances don’t change under rotations, space-time intervals don’t change under “Lorentz Transformations” in Special Relativity, which is why it is useful to have the notion of such a weird distance. Ordinary 3-D distances do change under “Lorentz Transformations” – as is demonstrated by the effect of “Length Contraction”.

The matrix that we’ve written in the above is (a representation of what is) called a “metric tensor”.

We can write the metric tensor for the surface of a “two-sphere”. That refers to the surface of the ordinary sphere in three dimensions, that we are accustomed to. It’s called a two-sphere because we are talking about the surface of a sphere in 3-D – which is 2-dimensional. Note that this metric varies from point to point (it’s a function of r and \theta) and hence, is a tensor field:


[dr d \theta d \phi][ 1                          ][ dr       ]
                    [    r^2                     ][ d \theta ]
                    [          r^2 sin^2(\theta) ][ d \phi   ]


Finally, any ”Riemannian Manifold” (curved spacetime) can be described by the metric tensor and its derivatives. So the metric tensor plays a central role in General Relativity. Formally, space-time intervals are written in the following manner:

The above follows a notation called “Einstein Summation Convention”, which my 17-year-old friend already knew, which can be read from other sources.

My first week at TIFR

Today marks the end of my first week at TIFR. So far, this place has been amazing. Let’s make a quick summary of plus points and minus points:

Work environment:
I’ve currently settled on a desk in the students’ room with my laptop and just enough space to keep my books. Air conditioned, Wireless net access. I’m surrounded by a lot of PhD students. They work a lot and that’s good because it motivates me to work as well. It’s so nice to see the next generation of scientists pacing up and down thinking, occasionally writing a few equations (that interestingly seem at least remotely familiar!) on the board. I like the work environment, although sometimes I wish it were cleaner – but after all, I’m used to dirty desks!

Lectures and other stuff:
We’re currently hearing from various departments about their work. So far, we’ve heard from 6 departments. Some of the speakers were very impressive, while some were talking to their colleagues and not to students – making their talks drab. Today, we heard from the condensed matter physics group, and we also had a nice discussion after the talk. I’ve been learning something new, something totally different everyday!
It was interesting to see a non-scientist at TIFR saying “You should always try to do science with enthusiasm.” or something carrying a similar message, as he fiddled around with an interesting experiment saying, “The scientists at TIFR have done this to me!”. I enjoyed the fact that learning about the world around is so enjoyable – to everyone.

My project:
My project’s about hydrodynamics. My guide et al found new symmetries in the non-relativistic Navier-Stokes equation for incompressible flow. The symmetry group is the conformal group. Given the generators of the conformal group, I verified today that the Navier-Stokes equation is indeed invariant under the action of the infinitesimal generators conformal group. My summer project will be related to these symmetries.
Today, when I went to meet Prof. Spenta, the discussion drifted to Green’s functions. He explained to me what a Green’s function was in brief (I still need to think), and eventually pulled out a functional integral and said “This is what’s called a Feynman Path Integral”. I said, I don’t know this stuff. And the reply was approximately, ‘Yes! That’s the point! You don’t know this stuff – so try to think about it and reconstruct it – don’t read about it’. He’s always put in the point that the best way to learn things is to think about them and reconstruct them, and not by reading them up in the past few times I’ve met him. I liked that! I’m now left to figure out all by myself what a special conformal transform does, and how a certain Feynman path integral gives me a two-point correlation function!
In the last one week, I also learnt a lot from Frisch’s book on Turbulence.

Food:
Well, I have the choice of 4 canteens! That’s much better than IITM. I don’t complain. Food here is good. The only stuff I don’t like about it is the garlic. It feels great to have nearly authentic Mysore Masala Dosa in Mumbai! We don’t have a choice for dinner, though, and I nevertheless manage to eat roughly the same stuff every evening.

Peers:
My co-VSRPs in the Theoretical Physics Dept are pretty good too. I’m yet to interact with most of the PhD students. I have knowledgeable peers to discuss stuff with.

Accomodation:
We’re accomodated in a furnished apartment at a place called Wadala, which is an hour’s journey by road from TIFR. That’s a little pain, but the accomodation isn’t as bad as we thought it was initially. I feel it’s better than hostel back at IITM, but I do miss internet connection. It doesn’t matter that much because I get just enough time to sleep at the accomodation and spend the rest of the time at TIFR.

I did feel a bit homesick initially, but that’s the case with me everytime I face change. It’s something that happens when you don’t give your brain enough work – but I now have enough to pack my day already!

Overall, I rate the first-week experience as good

I’m going home this weekend and returning on Sunday evening. Our department will introduce its research activities on Tuesday, and I’m looking forward for that!