For myself, having performed as a solo artist, as well as in 
various sizes of ensembles, playing several genres of music, and 
having written pieces for many of them, I'd have to say that as 
a composer, I've delighted many times in the 'live' input from 
those performing my work..their 'interpretation' and 'addition' 
to my work was often beyond what I'd conceived myself.  This 
'serendipity' phenomenon is somewhat lacking in music that I've 
composed using csound or other software. Having 'ultimate 
control' for your music can be more of a burden than a blessing 
sometimes.
The live performer is much abler to be inspired by the moment 
and environment of performance than the composer with his pen or 
his computer.  He is limited by his talent and technique, of 
course, but a top notch performer spends years in working to 
master his/her chosen instrument (which has also been tweaked 
and polished over decades to be as responsive to the artist's 
touch as the technology allows).  It follows that any composer 
who seeks to be a 'performer' using software will need to invest 
the same kind (and amount?) of time to master those tools..to 
turn them into his 'instrument'.  The question then becomes one 
of evaluating the value and need for seeking such mastery in 
order to satisfy the 'musical idea' that he or she is attempting 
to create.  As a csound composer this means lots of time thought 
and energy expended in both creating my instruments, then 
learning to 'play' them, and then, hopefully, using them to 
create aesthetically meaningful works that appeal to my 
listeners.  The listener is the final judge of my success.
If, as it seems, Mr Lansky has opted to move in a 'new' 
direction, I'd suggest that it's because his evaluation of his 
needs show that they can be more easily met in that way.  There 
is no such thing as composing without limits.  There are 
different sets and sorts of limits, imposed both in choosing the 
medium for the composition, and the 'musical resources' that are 
available to express the idea..not to mention the self-imposed 
limits that I seem to recall Stravinsky discussed.
Speaking of limits, one of the things I'd like to see added to 
csound is some way of adding 'rubato' instruments, 
'crescendo-decrescendo' instruments, 'portamento' instruments, 
etc. to the available ugens.  I know that these effects can be 
created within the note-for-note scores, but it would be much 
nicer if they could be applied to orcs like reverb or delay or 
panning are.  That may require a separate pass during the 
compilation, I guess.  I have noted that several works submitted 
to the website have included remarks about taking the csound 
output soundfile and tweaking it in other programs, like 
audacity, for instance.  It just seems like it would be nice to 
do it all in csound.  So, if it can be done, that'd be nice.  It 
would, I think, help put csound on solider ground as a 
composer's tool for any type of music.
Bob Foose

Unless I misunderstand you, all of these can be implemented as 
instruments.  For crescendo-diminuendo, all you need to do is create a 
phrase envelope in an instrument that runs for the length of the phrase 
to which you'd like to apply the cresc./dim, and output that envelope 
into a global variable, zak, or some other method of inter-instrument 
communication.  Then the sound-producing instrument just reads the value 
and multiplies by it to get the final value.  It's almost like a reverb 
in reverse.  Instead of lots of notes being combined into one 
long-running instrument, a single long-running instrument creates input 
that's used to generate lots of notes.

Rubato could be handled in a similar fashion, by having a small delay 
before the onset of a note.  The delay value could be controlled by a 
long-running envelope as above.  In principle it could work, although I 
think it would depend on exactly what you're doing.  I think it would be 
easier to use schedwhen or schedkwhen to trigger notes, though.

One standard way to create portamento is outlined at 
http://www.thumbuki.com/csound/articles/east/portamento.html, although 
that may be more work in the score than what you're looking for.  You 
can also use something like this instrument, by Russell Pinkston (from 
http://ems.music.utexas.edu/dwnld/orc/portrfp.orc)

	instr	1
iamp	=	p4
ioct	=	octpch(p5)
irate	=	p6
	if	(p7 == 0) igoto continue
iprev	=	octpch(p7)     ;optionally, specify previous pitch
continue:
idur	=	abs(ioct-iprev)/irate   ;compute duration of portamento
koct	init	iprev                   ;koct starts on previous note
	if	(ioct == iprev) goto audio  ;if no change, skip over...
koct	linseg	iprev,idur,ioct,1,ioct
audio:
asig	oscili	iamp,cpsoct(koct),1     ;function 1 has the waveshape
asig	linen	asig,.05,p3,.1
	out	asig
iprev	=	ioct                    ;remember previous pitch
	endin

Here p7 specifies the previous pitch, but if it's omitted (yielding a 
value of 0), it will remember the previous value to create a smooth 
portamento.  I've never seen this documented, but it appears to be (or 
at least used to be) a well-known feature.

Using this instrument requires some care since all notes to be played 
portamento must use the same instance.  If you want to have multiple 
lines, partial instrument numbers (i.e. 1.1, 1.2, etc.) are necessary. 
Also, the notes of a single line cannot overlap.  Finally, the first 
note for each instance must specify a value in p7, and then the next 
must specify a 0 before you can omit p7 (because score values carry).

John Lato

Robert or Gretchen Foose wrote:

> Speaking of limits, one of the things I'd like to see added to csound is 
> some way of adding 'rubato' instruments, 'crescendo-decrescendo' 
> instruments, 'portamento' instruments, etc. to the available ugens.  I 
> know that these effects can be created within the note-for-note scores, 
> but it would be much nicer if they could be applied to orcs like reverb 
> or delay or panning are.  That may require a separate pass during the 
> compilation, I guess.  I have noted that several works submitted to the 
> website have included remarks about taking the csound output soundfile 
> and tweaking it in other programs, like audacity, for instance.  It just 
> seems like it would be nice to do it all in csound.  So, if it can be 
> done, that'd be nice.  It would, I think, help put csound on solider 
> ground as a composer's tool for any type of music.
> Bob Foose