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On Music: the use of brass in Scheherazade

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Today's an exciting day for me here at the _floss. I'm kicking off a brand new feature called ON MUSIC, which I hope you're gonna enjoy reading as much as I will posting.

The idea behind ON MUSIC is this: every week or so I'll be writing about something to do with so-called "classical" music. I put it in quotes because I really hate the label. But the alternatives aren't much better: "concert music" "“ "longhaired music"??


So until we come up with something better, classical it is, and classical will be the theme of this feature. To help launch ON MUSIC, I'll be posting one a day for the next 7 days or so. The theme of this batch will be the instruments of the orchestra.

So let's jump right in then. The orchestra, as many of you probably know, is made up of four basic groups of instruments: strings, brass, winds, and percussion. Today we'll be listening to some hot brass playing in an excerpt from Russian composer Nikolay Rimsky-Korsakov's Scheherazade, written in 1888 and based on The Book of One Thousand and One Nights.

Want I'd like to bring to your attention is the variety of different ways the brass section is used in this 2-minute excerpt. Listen to the punctuating flourishes that punch out the main theme in the beginning of the excerpt. Rimsky was a masterful orchestrator. He even wrote a book on orchestration techniques which composers still use in school today. Listen at around 44 seconds in for the amazing staccato triple tonguing... that rapid fire sound from the trumpets. Then at about the 1 minute mark, he uses the trombones and tubas, later adding trumpets, as well, to recapitulate the main theme in a very large way, with bravado and breadth. Three very diverse dynamic ways of writing for brass within the space of a couple minutes. If you don't already know Scheherazade, be sure to download a copy to your iPod. I recommend the Von Karajan recording, though just about all of them are good enough to begin to get acquainted with this jewel.


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iStock // Ekaterina Minaeva
Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
May 21, 2017
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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Name the Author Based on the Character
May 23, 2017
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