If I had spend a career in one certain band playing basically one kind of music in one kind of venue, I could probably narrow it down to one. At least, one KIND of bass and backups (because stuff happens on the road, wear and tear, etc). But I'm currently taking all the work I can get, and work is slow, and diverse. There are times when a P with flats will do, and that's what I prefer. But certain situations I need a bass with rounds for at least ONE song per gig, and I don't like to swap instruments onstage (I almost always use ONE BASS per gig) . Or, I might need a 5. Or I might need a fretless. And do they get by with flats or do I need rounds? I hate constantly swapping strings so I keep basses around with each. And I need my DB for jazz gigs, because I get called for playing that specific instrument. Just on my regular Sunday AMs at church, every week is different; different personnel, different songs, same songs different arrangements, different vibes (from acoustic country to full out rock to synthy electronic sounds). Seems like its always something different and I've responded by keeping more instruments around than my wife would prefer!