I've built forty or so box guitars both 3 and 4 stringers fretted and un-fretted, Mag and piezo piclups. Over time I settled on a three stringer with no frets and a mag pickup. After playing for three or four years, I felt like I had pretty good control of the instrument and could play what I wanted. The problem I ran into was that a three stringer all by itself doesn't produce a full music sound. I needed a bass, drum, etc.
Well, that wasn't going to happen based on where I live. Just not a lot of players around. Then I came across a couple of guitar backing tracks on line and downloaded a few. Once I got one in the right key and did a bit of practicing, I suddenly realized how good a three stringer could sound with some back up.
I found that there are hundreds of good quality backing tracks free online and with the use of Audacity, I can tweak them to whatever key I need.
I've found good tracks for Allman Brothers, SRV, Dire Straits, Marshall Tucker, Santana, Steely Dan and many more. A good library of backing tracks can make you sound good in a hurry.
Here are a couple of examples