This is supposed to become a small music synthesizer program. The program will
output raw audio signal to stdout so you need to pipe it to a player eg.
aplay. It doesn't yet play anything other than some sine waves, though...
mkdir build
cd build
CXX=g++-5 cmake -G Ninja ..
ninja
cd build
src/syn ../data/sine1k.json | aplay -f cd -c 1