[CM] help with "ghosts" example from Metalevel book

[Johannes Quint]

have a look to 'ghosts' in the help-menu:

help/examples/ghosts.scm	

Am 03.03.2016 um 20:37 schrieb Rob Howiler:

> Hi again everybody.  This:
> (define (ghosts)
>  (process repeat 12
>           for here = (now)
>           for ahead = (* (+ here .5) 2)
>           for main = (pick-range 53 77)
>           for high? = (>= main 65)
>           for amp = (if high? .6 .4)
>           for rhy = (pick-list '(1/16 1/8 3/16))
>           do
>           (mp:midi :time here :key main :dur (rhythm->seconds rhy 60)
>                    :amp amp)
>           (when high?
>           sprout (hitone main ahead)
>           and sprout (riff main rhy) at (* ahead 2))
>           (when (= rhy 3/16)
>           sprout (thump main (+ here .5)))
>           (wait (rhythm->seconds rhy 60))))
> (sprout (ghosts))
> 
> This works fine to define (ghosts).  (ghosts) produces no sound just #<lambda ({time}-2239)> in the listener window.  Running (sprout (ghosts)) gives me the hitone sound, but no advancement to the next pitch and it generates this in the listener window (I see that “at” is the unbound variable, but I can’t figure out how to fix it):
> 
> #<unspecified>
>>>> Error: at: unbound variable
> ghosts: (lambda ({time}-1860) (let* (({wait}-1... ; args: ("~A: unbound variable" at)
> ghosts: ((* ahead 2))                             ; ahead: 1275579.145172206
> ghosts: ((when (= rhy 3/16) sprout (thump main... ; rhy: 3/16, main: 75
>                                                   ; here: 637789.072586103
> ghosts: (call-with-exit (lambda (return) (if (... ; high?: #t
>                                                   ; amp: 0.6000000000000001
> ghosts: (sprout (ghosts)) 
> 
> Thanks again for your help and your patience.
> Rob
> 
> ------------------------------------------------------
> Dr. Rob Howiler
> Academic Computing Services Coordinator
> Assistant Professor of Music
> rhowiler at presby.edu
> (864) 833-8324
> ------------------------------------------------------
> 
> 
> -- 
> 
> ------------------------------
> <http://www.presby.edu>
> 
> _______________________________________________
> Cmdist mailing list
> Cmdist at ccrma.stanford.edu
> https://cm-mail.stanford.edu/mailman/listinfo/cmdist

 

Johannes Quint
www.johannes-quint.de

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://cm-mail.stanford.edu/mailman/private/cmdist/attachments/20160303/339ec614/attachment-0001.html>