Daily Archives: February 23, 2010

lectureNotes_musth2 musicTheory2

(musTh2) Sequences and recent work

I’m in the process of catching up.

The handouts from Dr. Oravitz should be the most helpful thing you have on the topic of sequences. I’ve posted them in my iLocker 112 folder (Common harmonic sequences, sequence repertoire) if you need to get another copy.

A few words about sequences to reinforce some key points.

Know the common sequence types by root movements.

  • descending fifth
  • Pachebel (descending fourth, ascending second, resulting in an overall descending third)
  • 5 -6 exchange
  • descending second 6 – 3

The descending second with 6 – 3 chords is the only sequence that is usually comprised of a one-harmony segment.

The Pachebel sequence is obviously a two-harmony segment, since the driving movement of the sequence is to descend by thirds. The third descent is why I refer to it as a descending fourth/ascending second sequence, rather than an ascending fifth/ascending second. The root movement is the same, but the latter way of describing it suggests the sequence ascends by sixths.

The descending fifth sequence is less obviously a two-harmony segment, but usually the melodic segment will traverse two harmonies to emphasize a descending second movement. For example, starting on i in c minor will give root movements of C – F, Bb – Eb, Ab – D, most likely moving to G (V) and breaking the sequence. Notice the descent comprising the first root of each pair of harmonies: C – Bb – Ab, followed by G. Creating a two-harmony segment allows for a melodic sequence with each segment a second below the previous one.

A descending fifth sequence using all seventh chords requires an alternation between complete and incomplete seventh chords. Upper voices move either by common tone or step-wise descent, with the root doubled in the incomplete seventh chords.

Inversions are always possible in a sequence. Using inversions doesn’t change the basic sequence type (classified by root movement, not bass movement), but it may change the voice leading. With descending fifth progressions of seventh chords, alternating between a root position seventh and a second inversion seventh (4 – 3 chord) allows for every chord to be complete AND have EVERY voice move either by common tone or descending second.

assignments_cm3 computerMusic3

(maxmsp) MSP reading and tutorial assignment 1

The documentation and tutorial text is online at:

http://cycling74.com/docs/max5/vignettes/intro/docintro.html

You can read online without having the application.

Read the following sections of the documentation for MSP:

  • MSP Introduction
  • How MSP Works
  • Audio I/O

Go through MSP Tutorials 1 – 5.

These tutorials do not require you to modify anything, but I want you make a list of concepts and objects covered as a study guide for yourself. Turn in the study guide to me via email by 3/1/10.

computerMusic3 lectureNotes_cm3

(maxmsp) MSP basic demo patchers

Demo patchers from yesterday’s lecture are in iLocker. Look for patchers MSPBasic1[a - e].maxpat.

Outline of topics covered:

  • Digital Audio basics relating to how computers generate audio samples (in blocks, or vectors). The larger the vector sample size, the less strain on the computer, more latency.
  • Audio Rate and Control Rate, pertaining to patch cord connections and the rate at which they are computed.
  • ~ denotes audio objects (tilde looks like a sine wave)
  • dac~ and EZdac~ (and their related messages: start, startwindow, and stop)
  • basic objects: cycle~, *~ (gain).
  • The reliance on floating point numbers for messages, rather than integers
  • audio discontinuity leading to clicks requires use of line~ for smoothing message changes, especially for amplitude
  • replacing the sine wave table used for cycle~ with an audio signal of your choice (as long as it is 512 samples).