My second choice would probably be early 1700's - maybe 1720 or around there somewhere. I'd want to visit Bach, Vivaldi or Handel and try to weasel my way into a position as assistant or something (maybe by "composing" pieces I already know ;-)).
I would also choose something along similar lines, for two reasons:
Watching Bach play a keyboard instrument, conduct a Cantata (or maybe one of the Cafe Zimmerman's keyboard concertos) would be absolutely amazing, really no words to adequately describe what such an experience would be like.
And two... somehow making an effort to preserve the large amount of Bach's work that has been lost over the years. In fact, after his death, some of his autographs made their way from the Tomaskirche to the local butchers, where they were used to wrap meat. What an absolutely tragic loss. There was another composer (the name of which I can't recall ATM, but someone that Bach studied and was quite familiar with), who's entire, completely preserved musical output was destroyed when an allied bomb obliterated the basement of the church they were stored in. Makes me want to cry just thinking about it.
On a brighter (and slightly OT) note, I'm going to see guitarist Paul Galbraith perform next Tuesday. I can hardly wait! :-) I also managed to make it to see my favorite pianist, Andras Schiff, perform at Zellerbach Hall in Berkely last October. The tickets were actually a birthday gift from my girlfriend... (and I think I'm going to have to marry her now. ;-))
