We have all heard it everywhere:  the iPhone "tri-tone" notification sound.

It is a commonplace element in our daily aural landscape.  It's recognizable enough to be included in modern movies and TV shows, almost completely replacing the electronic "chirp" as the notification of choice on network police procedurals and dramas.  You all know it, but in case you can't quite bring it up, here it is:
Simple, right?  A three-note sequence, played on a synth marimba.  Attention-grabbing without being overbearing.  A nearly-perfect little bit of noise.  

What we don't always stop to consider, however, is that sound was designed.  Like so many other bits of audio input in our lives, there was care and consideration put into the making of that little three-note riff.

Kelly Jacklin, designer of the "tri-tone" sound, goes into some detail on the thought process and the mechanics of creation surrounding this little iconic bit of audio.  I find it fascinating how she handles the permutation of options (MATHMATICALLY!) and then auditioned each one.  She includes a short track of rejects in her post as well.  

One final detail of note is that her sound was not designed for the iPhone at all, but for a piece of software written by a friend, that was bought by Apple and eventually turned into iTunes, which eventually migrated the sound onto the original iPhone.  Interesting and inspiring how people's creations can take on a life of their own, far beyond the original intent of the creator.  
I have been experimenting with MOOCs; that is, Massively Open Online Courses.  These are online classes that you can take, often for free, hosted online by institutions of some prestige from all over the world.  There are several MOOC hosts out there, but the one that I am currently using is coursera.org

For my first class, I chose Introduction to Music Production, presented by Berklee College of Music.
As part of that course, I had to create a five minute video explaining the difference between microphone types found in the common home or small studio.  Below, is the video: