I had started with trumpet,and played up untill H.S..My Family moved to a new town ,and the school band was terrible and years (literally) behind what I had become accostomed to.I have always been drawn to beats ,and drum patterns,and would often memorize drum parts in band,so bass seemed like a happy medium between drumming,and my melodic background.Its the best of both worlds.I've never been particularly drawn to being a soloist,prefering short fills and accents to the music,and it seems playing bass allows you to play busy in the lower register w/out getting in the way of the melody(unless simplicity is called for).Ultimately I find bass more freeing for me.