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Using Computers for Sophisticated Music Analysis
Tom Avril writes "Need an accompaniment for your melody? Seeking a virtual dancer to try out your new choreography? Or perhaps you're making a new TV commercial, and you need a snippet of music that sounds something like Radiohead, but a bit more mellow. Increasingly, sophisticated software can help with these sorts of tasks. We got a look at the latest from the nascent field of Music Information Retrieval, after its conference in Philadelphia: 'A key part of the conference each year is the announcement of results from a sort of software shoot-out — a competition in which various universities pit their music-analysis algorithms against one another. Entrants from more than a dozen countries competed in 18 tasks, using their computers to "listen" to selections of music, then identify such things as the genre, mood, composer or title. The eventual goal: to help people search for music they might like by combing through millions of audio files in a database. ... In another task, the computer had to identify tunes that someone hummed. "The idea is, you go into the karaoke bar and start humming, and the computer retrieves your song," Downie said.'"
I'm not a Luddite. But...
Is there some value to being able to recall a song, or at least to using your brain to perform the exercise of recalling from memory? This can effectively replace our need to perform this task. (New iPhone app: Hum into it and it will ID the song!) Extend that to all such tasks, which we generally regard as getting in the way of us doing what we really need to.
Example: Calculators very effectively replaced log tables, and we are all grateful for that. But they have also replaced valuable manual math skills, effectively robbing young people of a certain amount of conceptualization we now reserve for mathematicians, if for anyone.
We may be creating technology which will gradually make us a non-contemplative people, living only in the moment. And if you live in the moment, you forget the past, allowing those in control to make you repeat it.
Help fight poverty: Punch a poor person.
One of my senior projects for college used a very similar but more detailed schema in recognizing musical patterns.
In musical terms, a step is the amount of change from note-to-note. The Parson Code is limited in which it only indicates the direction of the pitch, and not the amount. I simply took account the actual half-steps used between each pitch. Like the Parson Code, it would ignore the rhythm, and easily account for identical melodies that are in different keys.
Minuet in G would look something like this:
-7 2 2 1 2 -7 0 9 -4 2 2 2 1 -12 0 5 2 -2 -1 -2 2 1 -1 -2 -2 -1 1 2 2 -4 4 -2
It was fairly easy for me to find an exact match using that encoding, or match to a certain %, since more information is provided than using the Parson Code method.
I feel that this is not far off from how the human brain recognizes melodies as most people do not have perfect pitch, but relative pitch in which we can recognize a certain melody by the difference in pitch changes even when the melody is using a different rhythm, or is in a different key than the original.
Last.fm may be good, but here's the Pandora summary for why it played a particular song (James Taylor's Handy Man):
the song features pop rock qualities, folk influences, a subtle use of vocal harmony, use of string ensemble, major key tonality, a vocal-centric aesthetic, a good dose of acoustic guitar pickin' (sic) a dynamic male vocalist, electric pianos, acoustic rhythm guitars, romantic lyrics...
While a sophisticated computer may be able to detect some of these characteristics, I stand by my comment.
If you've looked at many waveforms in a recording program you'd know that rhythm and tempo are pretty easy to identify. I've studied algorithmic analysis of music and tempo. Rhythm and pitch are all reasonably analyzed because they're easily identified by math (what computers are made for). It's identifying things like timbre that set the mood based off cultural experience, etc that are hard to nail down with a computer. A performer can play 1 note many different ways to set many different moods and computers have trouble analyzing why it sounds different to us because it is hard to compute a lifetime of musical experience and expectation.
Minuet in G would look something like this:
-7 2 2 1 2 -7 0 9 -4 2 2 2 1 -12 0 5 2 -2 -1 -2 2 1 -1 -2 -2 -1 1 2 2 -4 4 -2
Anyone in particular's Minuet in G (Bach? Mozart? Beethoven? Me?), or all of them? And I thought the key didn't matter, so that would be all minuets?
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