Bass, mandolin, guitar and banjo.
Started with bass just because. It's bad-ass. Then I started dating my first girlfriend as a freshman in high school, and wanted to impress her by writing her a song. I figured singing and bass alone would be a bit too sparse, so I wanted to go with something else. A mandolin is eight strings, but it's actually four pairs of strings. And while the bass strings go E, A, D, G, on mandolin the pairs of strings are G, D, A, E. Plus it's romantic. So I went with that. After a while I figured as long as I'm playing mandolin I might as well learn guitar, so I taught myself guitar. Later on down the road, I fell in love with the banjo, and bought one. Banjo is incredibly easy to play, too.