Hi Mac. To play midi files using Kmid you need a Creative/Audigy soundcard that has a wavetable synth, and uses the emu10k1 driver. On the CDROM that came with these cards, there is a soundfont, .sf2, that needs to be loaded, and then you can play midi files, using Kmid for instance.
As an alternative you can install TiMidity. http://timidity.sourceforge.net
To use TiMidity you will need to get a GUS (Gravis Ultrasound) patch set. Just type "gus patches" (without the quotes) into google,and try to find a complete set, rather than individual patches.
If you want help in setting TiMidity up, post back.
All the best. Nigel. aka farpoint.