Priceless Pricing

Listening to Jazz feels like time well spent, despite a limited understanding of this beautiful American art-form. John Coltrane and Miles Davis are especially close to heart given their affection for India's native music that also influenced how they played. Miles is recognized for paying attention to the 'space between the notes' as noted in this blog:


"Among Miles’ trademarks was his emphasis on the space between the notes as much as the notes themselves.  Silence was key to his music.  He was so cool he didn’t feel the need to jam up every measure with noise.  Sometimes it’s better to just stand there and not do something."

It is well known that silence is an important tool in the hands of an expert stand-up comedian or a novelist. In the world of ORMS, optimally scheduling working hours for airline crews is really about paying close attention to their silent periods of rest. In the world of pricing optimization, it is imperative to recognize that a customer always values something else in the product in addition to price. To usefully optimize price, we must accurately identify its priceless attributes.

Update: January 11, 2013
Richard Marcus, former CEO of Neiman Marcus:  “Price is important, but quality is remembered long after price is forgotten, as are qualities of uniqueness and originality.”

Update: February 06, 2013
Competing beyond price to maximize customer loyalty: "...“Attractive prices are an effective means to get people in the door, but it’s not enough to maintain loyalty, drive future purchases, and generate customer recommendations..."

Update: May 30, 2013
Price Perception: " ....it’s not about price, it’s about what am I getting for that price"

The Optimal Playlist

One of the problems with neighborhoods in parts of Connecticut is the lack of sidewalks coupled with crazy drivers (probably from a neighboring state to its left). To avoid getting run-over, I decided it is safer to do my walking on the treadmill. I'm now getting all the exercise a creaky researcher needs, but I'm not getting anywhere. To overcome this monotony, I hooked up my old iPod-classic for company, but it's time-consuming to generate my preferred playlist : start off with some up-temp music for motivation, then switch to cruise mode, and tone down after my 30/60 minutes of walking.

In India, we have the concept of 'Rasa', a Sanskrit untranslatable that very roughly speaking, includes notions of experiencing certain emotion(s), themes, ambiance, genre, etc. So the sequence of Rasas  matters a great deal. Furthermore, I like to listen to complete songs and hate to end a virtuoso Carnatic performance half way when the exercise session-clock runs out. Furthermore, there are so many languages in India and many have their own pop-culture, folk, and classical genres in instrumental as well as vocal modes, and I prefer a diverse sampling of these to feel more at home.

Putting all this together to achieve an optimized playlist requires a constraint-programming approach. If I also want to optimize a certain objective (e.g., stay close to 12 songs), this turns into an exercise of solving an associated discrete decision optimization problem that can be stated as follows:

Find (preferably) 12 complete non-repetitive songs in a preferred sequence that lasts (almost) exactly 60 minutes, and includes at least n(i) songs having user-specified attribute (i), i = 1, .., n.

If we restate the attribute requirement as a soft-constraint by creating a score-table for including any attribute (e.g. 10 points for including a song with attribute i once,  15 points for two songs with attribute (i), 17 if three or more times) as opposed to the 'must satisfy' version stated earlier, then the playlist optimization problem can be posed as a attribute score-maximizing multiple-choice knapsack problem with a cardinality constraint, followed by a sequencing step. Even with a huge home music database, practical instances of the latter formulation may be relatively easy to solve via combinatorial methods (iPhone app?) and may not require expensive MIP solvers. Then, as a second step, we can sort the included songs into another preference-score maximizing sequence to generate the final playlist, unless of course the sequencing requirements are not that simple (in which case, a more sophisticated optimization approach may be required).


Such an optimized playlist is also useful if you want to build an auto-pilot DJ for your next house party. If your approach can solve this problem on-demand, you would also be able to dynamically re-optimize the playlist after manual intervention.

It seems apt to terminate this post with a Carnatic-Western classical fusion piece.



Updated on March 30: The objective function above is deterministic so there is a good chance that the you will get the same set of songs to listen to each day, which is not very useful. To introduce diversity and exploit the fact that in practice you tend to get several alternative optimal solutions to such problems, add a small amount of clock-dependent noise to the attribute-score and sequence-preference score. This will likely do the trick.

Carnatic Jazz Fusion via Alto-Sax

This is a performance of a portion of the album 'Kinsmen' at U-Mass. The album's name is quite apt. The collaborators are Rudresh Mahanthappa, U.S born Jazz Musician, and Kadri Gopalnath, The carnatic exponent. This article in the New yorker reviews the album and mentions how these two wonderful musicians got together and realized their parents are both from Karnataka (my home state) in India. You can listen to this album here. You can follow the Dakshina (i.e., "South" in the Kannada language) Ensemble if you are interested. Rudresh has gone on further to work with Vijay Iyer, another acclaimed U.S born Jazz pianist, who in turn, is also part of the band 'Tirtha', along with personal favorite Prasanna (see link on the right side of this tab).

A vigorous discussion of fusion music in general, including more feedback on this album can be found here.

These may be the next generation of musicians who take Indian (and south Indian) music to the next level and enable it to reach an even wider audience. This blog post talks about Prasanna in this context.