High and Low Pass Filters

Took a very basic sound recording class a few years ago at the local community college I remember (I think) part of the studio process should involve applying a high and low pass filter depending on the instrument(s). Should that be a concern if you are recording only one instrument? And what would be general guidance for a regular dulcimer, a bass, a baritone etc.?  What if you throw voice into the mix? Just playing around with Audacity...