#lang racket (require oregano) (define my-sin (preset-instrument "sin-inst")) (param-slider "change frequency" 300 1000 400 (lambda (val) (set-inst-param my-sin "freq" val))) (param-check-box "synth on" #f (lambda (v) (if v (inst-on my-sin) (inst-off my-sin)))) (show-gui) ;; example: (sleep 0.5) ; (note-on my-sin 500 1) ; (note-off my-sin)