So I am a fairly new bass player, and I took my '71 P Bass to a local shop of ours to get fixed up since it had been sitting around since about 1976. I explained to him that I often tuned low and the strings were pretty loose. His solution was to put the top four strings from a set of five string strings on it, which he did. This seemed a little off beat and unusual so I've been looking around to see if it's a common thing and I haven't found much. He told me I could tune my top string right back up to E if I wanted, no problem. But I feel like that would be quite tight and I'm just not sure if that's alright. Can I tune my B string to E, and for that matter, is this bad for my bass? Thank you 

