This has puzzled me for years. Through its a subjective question and open to personal interpretation, nonetheless where does a bass grow into a different instrument? I have played 4 strings since the mid 70s. If you struck a single chord in those days the band would stop and say if you want to play chords, play a guitar. Bass lines then were all about the groove. As more and more bass players use 5,6,7 etc. strings, when does the instrument evolve into something else? These players are unbelievably talented and their music is magic (just listen to Zander Zon on a 4 stringer) but just curious to other bass players opinions.