wip/csound6 6.18.1 NetBSD

Csound is a software synthesis package in the tradition of so-called music-N languages, among which the best-known is Music V. It consists of an orchestra- and score-driven executable, written in C for portability. Since Csound is a computational language, it is highly flexible and efficient; complexity is gained only at the expense of computation time. Basically Csound reads some files and creates the result as a file on disk or, on faster machines, through a DAC in real time.