Assignment 3: Trying out Csound
Goal
To understand how basic Csound opcodes work and to listen to
sound produced by simple orchestra files.
Task list
- Read through the ‘toot’ tutorial at http://www.keele.ac.uk/depts/cs/Stephen_Bostock/webteaching/C-Sound_Tutorials/Index.htm
(also at http://www.csounds.com/toots/index.html) and
try each section by downloading the files and running csound on each one.
The command on music1 or music2 is simply csound followed by the .orc file
and the .sco file. E.g.:
csound -o dac toot1.orc toot1.sco
You should hear the sound generated by the orchestra file and played by
the score file. If you do not, contact me.
- Answer the following questions:
- In toot01, what happens to the sound produced if you alter sr in the
.orc header to 22050, and kr to 2205?
- In toot02, what happens to the output if you change all the note durations
(p3) in the .sco file to 2 seconds?
- In toot03, what happens if you reduce the attack time (p6) to 0?
- In toot04, describe the change in the output sound if you alter the
detuned frequencies to 1.001 and .999.
- In toot05, what change would you make to have the time of the delay
until vibrato starts come directly from p10 rather than be calculated
from it and from p3?
- In toot06, what do you hear if you use the GEN10 function method to
produce only even harmonics? [In particular, note that the fundamental,
being an odd harmonic is given amplitude 0].
- In toot07, alter the .orc file so that each note length is split into
two equal parts, and the p13 governs the length of the crossfade. For
instance, if the length of a note is 5 seconds, and p13 is 0.2, then the
first oscillator will sound for the first 2.3 seconds, then the second
oscillator will be crossfaded for 0.2 seconds, and then the second oscallator
will finish the note up to 5 seconds. [ You will need to alter the linseg
for kfade accordingly].
- In toot08, alter the use of p9 to be a ratio (between 0 and 1) of the
"wet" signal (with reverb added) to the "dry" signal
with no reverb. Thus if p9 is 0.5, the wet and dry signals will be the
same amplitude. If p9 is 0.8, then the wet signal will be 4 times as big
as the dry signal (i.e. 0.8 / 0.2). Use this file as the input for the
reverberator.
- In toot10, make the frequency parameter of the reson opcode (it's first
parameter) modulated by the output of a low frequency oscillator instead
of by a line envelope. [Look at the vibrato example in toot05 to see how
this is done].
Deliverables
The answers to questions 1-9. Where the orchestra or score
files have been changed, give the new versions.