Category: Music

A Phase-Aligned Oscilloscope for Web Audio

A music synthesizer should produce nice periodic waveforms when a note is played. We should be able to see that regularity when we visualize the sound pressure with an oscilloscope, here demonstrated with the Yamaha DX7 emulator: The Problem We can see the regularity, but hold on. The waveform is jumping around, flickering left and right. It doesn't […]

Yamaha DX7 and MIDI in JavaScript

Check the demo or find the source at This Yamaha DX7 emulator is my attempt to do something cool with the Web Audio APIs. The synth responds to MIDI input (make sure your device is hooked up before you start your browser) including pitch bend, mod wheel, and aftertouch.  I've added the ability to pan the operators for […]

Watermark Listening Test Results

Over the holidays, I looked at the data from the watermark listening test. My hypothesis was that the watermark added by Universal Music Group is at least as audible as 128 kbps MP3 compression artifacts. The test results support the hypothesis for certain types of music. The most important takeaway is that the UMG watermark is an enormous […]

Enable Mac Volume Control for HDMI and DisplayPort Audio Devices

When you hook up an HDMI TV or DisplayPort monitor with built-in audio device, you might discover that you can't change the volume with the Mac software mixer any more. Volume buttons on your keyboard won't work. You're expected to use the TV remote or volume control on the device. Here's a trick to get […]

Shuffle Algorithms for Music

Update, March 7, 2014: Improved shuffling has been rolled out on Spotify. More details at the Spotify Labs post, How to Shuffle Songs. Lots of users complain that Spotify's shuffle algorithms aren't really random. This can best be explained by a cognitive bias called the clustering illusion. Users aren't wrong to complain, though. What people […]

Music Streaming Snapshot

Monthly Users According to Facebook - February 2012 Service Launch Date Monthly Users % Change Spotify Oct 2008 15,800,000 +20% Pandora Jan 2000 9,200,000 +3% SoundCloud Oct 2008 3,100,000 +24% Bandcamp Sep 2008 1,200,000 +21% Grooveshark Jan 2006 1,100,000 0% Slacker Jun 2007 150,000 0% MOG Dec 2009 140,000 -30% Rdio Aug 2010 100,000 +43% […]

Universal's Audible Watermark

This is my personal blog. The views expressed on this page are mine alone and not those of my employer. Update, April 8, 2013: Can you hear it? Take a watermark listening test. Update, January 14, 2015: Check out the results of the listening test. A while ago, I wrote about my confusion regarding Weird […]

Mac OS X Speech Synthesis Markup

I put a Sound Blaster 16 in my first computer. It came with a CD-ROM full of goodies like Dr. Sbaitso, the talking psychologist. One app was called TextAssist and it had a special syntax that let you string together phonemes, specifying pitch, duration, even vibrato. I spent hours composing weird robot jingles. Itsy Bitsy […]