What ports connect special tyes of music instrument to sound cards?
Typical sockets on a sound card include Speaker, Microphone,
line-in, line-out, and perhaps others. When used for surround
sound, the jacks may take on different roles and thus be for front
speakers rear speakers, center speaker, side speakers, subwoofer,
etc. Older sound cards also had a joystick socket that could double
as a MIDI instrument socket with the right adaptor.