Sunday, February 25, 2007


This was a weekend of tinkering. One of the things I discovered was Moodbar --- a cute blend of signal-processing and UI design. The motivation for this toy was that intra-song navigation is still largely guesswork since one has to know in minutes/seconds where one would like to jump to in a song. Now why would you want to jump around a song? Well, if you're like me, you might want to jump to an interesting few bars of a musician's solo, for example. So rather than dealing with this antiquated interface:

this is what I can work with instead:

I'll point you to their paper for all the interesting details, but the gist of it is that for each few-millisecond slice of the song, the intensity of the power spectrum in the low, mid and high ranges is translated into R, G and B values respectively. What this means for those of you (yes you Jayita) who've forgotten signal-processing basics, bright shades mean loud bits, red parts denote bass-dominated parts of the song, while green and blue indicate more stuff in the soprano and higher regions. Here's what a few of my favorites look like:

"2 and 2" has 3 distinct regions corresponding to solos by Miguel Zenon (soprano sax), Joshua Redman (alto sax), and Eric Harland (drums). The horn solos are green, indicating a strong mid-range response, while Eric's solo is a mixture of bass (red) and high-frequency (blue) cymbal-work. It's also interesting to see the pattern of tension buildup and release in each solo; the colors start out dark, and build up to a bright glow towards the end of each solo (a common idiom in jazz).

Dream Theater's "Caught In A Web" has nice green highlights where James LaBrie's voice dominates the midrange. Now I know how to jump around those bits since I think he's typically the weakest element of the band's music (sorry Arjun!).

Surprisingly, jazz tends to display more structure in the moodbars --- probably because of the long solo sections featuring instruments in different tonal ranges. Bill Evan's "All of You" shows nice demarcations with Scott LaFaro's bass solo taking up the dark-red section in the middle followed by a short solo by Paul Motian on drums. Joe Henderson's blistering saxophone solo also shows up in bright green on McCoy Tyner's "Passion Dance".

Pop and rock moodbars are less organized, but song structure such as choruses (such as the bright loud cyan regions where "We Will Rock You" is yelled by the crowd) are easily identifiable too.

I should mention that the moodbar is available as a plugin to Amarok.

Tuesday, February 20, 2007

Let's Face It...

We've all had our bad days at math:

Monday, February 19, 2007

New Blog Home

Assuming DNS has updated, you should now notice that this humble blog is at Still hosted on Google servers (so I don't pay extra for bandwidth cost), but by mucking about with DNS and adding a CNAME alias from the hostname "blog" to, I get it all working quite seamlessly.

Saturday, February 10, 2007

Happy Birthday Ava

Coe's an uncle again. Congrats Sean and Amy :)

"Show" Off

That's what I'm going to do.

In the last 3 weeks I've attended five (yessiree!) shows (I love the Bay Area). First was Bobby McFerrin. Now saying that this man has an amazing voice is akin to saying that Beethoven's Fifth is a pleasant little ditty. He performed with Voicestra, an 11-member a capella group which had an interesting improvisational style for a choir: Separating them into the traditional platoons of bass, tenor, alto and soprano, Bobby would start a purely improvisational groove and get one section to follow, while leading off and improvising a melodically distinct groove with another section which wove seamlessly into the previous ones.

Knowing that I'd missed watching Ladysmith Black Mambazo perform in each of the previous two years that we've lived in the Bay Area, Jayita had made sure we didn't do the same for their appearance at Stanford this year. As expected, these jewels of South Africa were stunning. The tightness of their vocal harmonies are unmatched, even if the melodies got somewhat wearisome over the course of the evening.

A few days later, I was driving back up to Berkeley to catch Paco de Lucia and his group of flamenco musicians and singers. A true luminary of the flamenco guitar, he impressed us most with how easy he made it look. For me, an eye-opener was the performance given by the two female flamenco singers. I'd never heard a singing style like that ever. I'm definitely going to try to acquire some of that music.

Three days later, we were back in Berkeley for Kodo; a Japanese taiko drumming troup. The sheer visual spectacle of this art form can't be missed. The incredible physical endurance displayed by some of the performers, as well as the virtuosity in improvised rhythms made it an evening to remember. They performed on several different types of drums from the smaller rope-tightened ones, to the large o-daiko, measuring four feet across and carved from a single tree trunk. The piece composed for this beast was supposedly inspired by the sound of a mother's heartbeat as heard by a baby in the womb.

Final trip to Berkeley for the month: Wait, Wait... Don't Tell Me!, one of our favorite NPR shows was being recorded live at Zellerbach, so yesterday we toodled back across the bay. What's truly amazing is how much of the show doesn't make it to air. Between Paula Poundstone making repeated references to the phrase "crap a pineapple", just to see how the sign-language interpreters would translate, and Linda Ronstadt (the special guest) discussing the absolute uselessness of the brassiere, we rolled in the aisles.

Good times.