i think what you're talking about are soundfonts that take the place of midi instruments.
while the best ones aren't free there are quite a few decent free ones out there, but then you also need a player capable of using soundfonts. or it could just be you have a rubbish soundcard, the midi sounds on my card aren't too bad.
it's also possible that what you were hearing was the result of midi playing through a hardware synth or keyboard.
while the best ones aren't free there are quite a few decent free ones out there, but then you also need a player capable of using soundfonts. or it could just be you have a rubbish soundcard, the midi sounds on my card aren't too bad.
it's also possible that what you were hearing was the result of midi playing through a hardware synth or keyboard.