I was thinking about this "100 post" milestone thing. Looking back, my first-ever post was 11/9/08, so I can't make 100 in a year. Instead I'm setting my sights on the end of this year. Strap yourself in, the ride's about to get bumpy.
Birdsongs have dialects. Small differences in song accumulate until they produce identifiable differences. Learn these dialects well enough and it potentially becomes one of the easiest ways to tell where a given bird hails from.
Recently I was at a gathering of Reform Jews from around the country. It proved an interesting experience; within a group of Jews of similar ages, similar backgrounds, and similar religious upbringings there was not consensus about the melody for the evening prayers. There was definitely a large plurality, to be sure, and the variations were minor, but they stood out enough to be noticeable and to be clearly intentional, as opposed to missed notes.
It's possible most of these variants were improvisations, but I doubt it. My suspicion is these Jews sang the prayers differently because that's how they learned them. And where did they learn them?
One of the phenomena I've noticed in modern Reformed Judaism is most changes - small ones, such as new prayers, songs, and rituals; not big ones like policy change - stem from young campers returning home and bringing their favorite parts of what they did during the summer. I suspect that one could fairly accurately identify where people went to camp by looking at the variations in the songs they sing.
I could be wrong, especially given the strong centralizing forces in RJ like NFTY. Many of the songleaders at camps across the nation are learning the new songs and harmonies from the same source. This could also be the source of variations, as individuals make mistakes and innovations and pass them onto campers, but it is also a strong normative force.
I like these variations. I like that as I travel across the country I learn more of them. It makes my own experience richer, as I integrate the ones I like into my own style. I like the way they stand out. There's a great moment in the birkat when the melody I learned continues through a break in the melody everyone else used; the accidental solo was fun for me, but I think it's fun for everyone else too, giving them a little surprise in the middle of a familiar prayer.