Friday, May 14, 2010

Octobass and Harpolyre

Octobass has nothing to do with Octomom  :)

Cité de la musique in Paris is fun place visit. Adjacent to the Conservatory, it's a home to one of the world's best contemporary music orchestra, L'ensemble intercontemporain. In the complex there is a very good shop, plenty of space for workshops, seminars, educational programs, in addition to a fantastic auditorium... And there is a huge Musics Museum  -- Musée de la Musique -- where you can see more than 40,000 pieces of musical instruments, exposed chronologically so you get a feeling of how and why the orchestral music  evolved.

You can see many fancy instruments, such as octobass -- almost double in size with respect to a double bass (pic above). Berlioz apparently liked it a lot --for his huge orchestral experiments-- but since it was too large, the strings too thick... the instrument disappeared from all standards.

As you probably know, the range of frequencies emitted by a violin is between 200 Hz and 6000 Hz. Octobass instead diggs to extremely low frequencies: 16.3 Hz for the first string and we can normally hear only the sound starting from the 3rd string. A funny thing is that despite such low frequencies, we still hear the basic sound produced on first two strings, but we cannot distinguish between them. The reason for that is that our nervous system receives only the highest intereference of harmonics, which for the octobass appear to be at the same place for both of the first two strings -- despite the fact that the two basic sounds are different [that phenomenon is known as the Tartini effect].

To play octobass you need to play it outdoors or in a huge hall: if the first string produces a sound of frequency 16.3 Hz, then the distance to hear only one period of sound is 21 meter [i.e., speed of sound in air, 340 m/s, divided by frequency of a given sound]. In other words, a guy playing this instrument hears much smaller a sound than you as a receptor [the farther you are, the better it sounds -- provided you don't go too far away and lose the sound coming from other, smaller, instruments].

Here is how it sounds like: octobass & violin in La follia by Arcangelo Corelli

Another fancy example I thought was Harpolyre

When you see it, you immediately understand why it disappeared from the family of instruments: Just imagine the time it takes to tune this thing! :)

1 comment:

  1. Hello,
    My Husband it the player of the harpolyre. He also has a CD of the music of Sor on it.

    We are coming to Paris this summer. John would like to play the Sor music in Paris someday if you have any connections.

    He will be playing at the Museum of Music in Barcelona soon as well. We are in contact with them at this time.

    Thanks for posting John!