Thank you! Adding those additional parameters enabled a build. (There were some warnings but they were just "falling back to library file" items that didn't seem crucial.):
clang++ libopenmpt-helloworld.cpp -std=c++11 `pkg-config libopenmpt --cflags` `pkg-config portaudiocpp --cflags` `pkg-config libopenmpt --libs` `pkg-config portaudiocpp --libs` -o libopenmpt-helloworld
I did, however, encounter another problem. I tried invoking my newly-built command line program with a few different Tracker files in various formats, including the simplest-possible IT file with a single sample, that I made myself. No matter what file I choose, I get the following error -- here's an example:
$ ./libopenmpt-helloworld tempest-acidjazz.mod
Error: Sample format not supported
EDIT: The line causing it is as follows:
portaudio::BlockingStream stream( stream_parameters );
EDIT 2: I downloaded a PortAudio "hello world" for C++, that just plays a Sine Wave, and that builds and executes fine.
Thanks once again for any help or things to try! I still feel like I'm probably missing something basic...
rs