so, i'm going out in 2 hours; i just went to get my fiddle, and the D string is broken! (i'm very unimpressed; these are new Helicores which are barely 2 months old.)

unfortunately, the only spare set i have is used Dominants. so, do i:

a) replace only the D, and have mismatched strings until i get a new one, or
b) replace G, D and A, and have all Dominants, but spend most of the night tuning, or
c) take the mandolin instead and hope i can actually play it?

is it normal for strings to break that quickly? i've had Dominants last six months or more...

I think, from a personal point of view, I would go for option (a), assuming that you could get a new string within the next day or two. But it depends how important the event is that you are playing in, and if you are happy playing on mismatched strings.

It isn't normal for strings to break so quickly. I use helicores most of the time, and have only ever replaced them when they are worn. I can't remember the last time I had a breakage. Maybe you had a freak bad string. Was it fitted properly? (No offence meant - just something you could check for.)

If you bought the strings from your local shop you might be able to get it replaced as it sounds as if it might have been faulty -- Helicores should last much longer.

I used to find that Eudoxa As were prone to breaking very quickly, but the shop was very good about giving me new ones. In the end I gave up on them altogether.