Continue with the lab documents pd4-travis.pdf and pd5-moreTravis.pdf found in the same course documents directory:
(from outside via web) ccrma.stanford.edu/courses/220a-fall-2005/docs
(from inside via file system) /usr/ccrma/web/html/courses/220a-fall-2005/docs
Patch files which you'll need to access for these are grouped in a new pd sources directory: (below the first one)
(from outside via web) ccrma.stanford.edu/courses/220a-fall-2005/pd/travis
(from inside via file system) /usr/ccrma/web/html/courses/220a-fall-2005/pd/travis
Follow the instructions for turning in homework online. There's a specific format so that files can be seen by the world via the homework factory.
Every time that the factory is viewed by a web browser it will check for the existence of for example, the first assignment, by looking for a file under each student's home directory (where ~<user> is Unix shorthand for user's home e.g., ~cc equals my CCRMA home directory, /user/c/cc).
~<user>/Library/Web/220a/hw1.wav
The assignment is to create a demo based on the Travis patches using prescribed source material. Like all future work, the soundfile linked to the above file pathname should be
file format: .wav
sample rate: 48kHz
resolution: 16-bit
channels (unless otherwise specified): 2 (stereo)
The sound source for the demo (to play with alsaplayer) is
~cc/snd/220a/hw1-src.wav
The demo file should have a duration between 90 to 120 secs in its final form.
Use audacity for recording the Pd output and for editing different takes into the form required by the assignment. Here's how:
Set up the usual jack / Pd audio as above and test with a patch to make sure sound is working
Launch audacity (either from a terminal command audacity & or from the menu: Applications: Sound & Video: Audacity)
Open audacity's preferences (either <ctrl>p or from its menu: File: Preferences)
Set Audio I/O for Playback to Jack...: alsa_pcm and for Recording to Jack...: pure_data_0 and then channels to 2 (Stereo)
Set Quality for Default Sample Rate to 48000 Hz and for Default Sample Format to 16-bit (leave the other fields alone)
Set File Formats for Uncompressed Export Format to WAV (Microsoft 16 bit PCM) (leave the other fields alone)
Hit the OK button
On the lower left, set the Project rate to 48000
Hit the big red record button and play some Pd sound, the levels should change obviously and a waveform appears
Stop recording, rewind, test the playback and then export the recording with the menu command: File: Export As WAV
Quit audacity without saving the project, relaunch it and see that all the presets above have been kept ok (they should have been)
Bring in the just-created .wav file with File: Open
There are two forms for your audacity work: tracks saved as .wav and entire projects saved as .aup files. Source clips and final products are in the former format and edit sessions that are in progress are in the latter.
Use the usual mouse and cut/copy/paste commands to select, trim and position clips. Multiple layers are automatically mixed to 2 channels for previewing and export. Practice with it to get a feel for editing and mixing. See the Help menu for questions, overall it's rather intuitive and a pretty useful kitchen knife.
Now about that 90-120 sec demo. We're calling the expected form Melody / Rhythm / Polyphony (with apologies to Luigi Nono and his 1951 composition for woodwinds, percussion and piano Polifonica / Monodia / Ritmica). Accordingly, work your demo in three sections using transformations explored in Travis's patches.
Single-voice melody in the first section, create some kind of tune or melodic effect
Rhythm in the second section means getting the source material to loop, recur, in a beat-oriented, or metrical way
Polyphony is multiple musical layers i.e., simultaneous voices or tracks, which can be more or less coordinated or independent of each other and can be doing anything you invent
Decide whether the transitions between sections will be smooth or surprising, as you wish. Please restrict yourself to the source material in ~cc/snd/220a/hw1-src.wav
...and let's see what we get. Think about filling out the spectrum, bass to treble over the course of the demo. Pitches from the basement to the top, and timbres that are deep or strident. Also, keep an eye on the final amplitude range. It should average in the middle of the range and never get so strong that it clips (distorts) the waveform.