I have returned to the bass after a 30-year hiatus after finding a good deal on an instrument and combo amp......I went with a 4 because it's what I was used to, but wonder if I made a mistake. I have researched tuning, but still have some questions: Does drop D tuning mean you tune the E string down to D? or...why couldn't you put a set of 5 strings on a 4-string bass and have B E A D? Would the B not fit in the space for the E? I'm sorry if these are dumb questions, but I want to be able to play notes lower than E without buying another bass...and I do like my skinny jazz neck! I would eventually like to play in a C&W cover band when I get back up to speed. Any advice would be appreciated.