Both my basses are 5 string, but I consider 4 as the standard, I choose to play 5's as I like to have the option of varying some of the riffs I play with some lower notes, I was probably inspired to do thos by listening to the likes of Stuart sender on tracks like space cowboy!
Got a gig in November with aziz ibrahim, he who replaced john squire in the stone roses and wrote a fair amount of ian browns first solo album. He's playing on two of our songs and we're also doing two of his tracks, corpses and my star, both of which go down beyond E. No problem on my 5, but I am told he will insist I play it on a 4 strin p bass, detuned, cos that's what sounds right!
Tony