I string my Martin D-28 and my Guild 12-string with D'Addario Phosphor Bronze lights. Both guitars are quite loud and quite old so they do best with light strings. I tried Adamus lights for quite a while and like them, but they are much harder to find nowadays.

The D'Addario's stay bright a reasonably long time, and though I change tunings, and sometimes bang out the Delta blues, I have never had a breakage problem. I had that problem with several other string brands, including Martin.

Some performers seem to break strings with some regularity. At first I thought it was their playing style, but I think now it is more the string or tuning peg's fault.

One of my favorite folk memories comes from the old Hootenanny show. I believe it was Paul Prestipino (corrections welcome) backing the Chad Mitchell Trio. He broke a string during a song and changed it, all the while playing enough guitar to keep the song moving.

I remain in awe and would not believe it if I hadn't seen it on TV (which may mean I'm truly gullable).

You may want to check the thread "Black Diamond Strings" to get Guy Clark's opinion of one brand.

Roger in Baltimore