Do you NEED a 5? The obvious answer is NO! There have been thousands of hit records recorded and millions of memorable concerts and shows performed with 4-string basses. I bought a 5-string several years ago and tried to ease my way into getting used to it. I tried for two or three months, decided that it was more trouble than it was worth and put the bass in the closet. After two or three years, I got it out again and decided that the B string gave me some extra flexibility and I’m enjoying it. Right now, I’m looking at new basses and am not even considering a 4-string.