The music wire has worked out fine. I rode the bike for a commute distance of 26 miles total today, and the handlebars did not budge one bit. I've put close to 75 miles since I wrote post #22 above.

If my co-worker shows up at the site I'm at this week, I'll compare my handlebar post(s) to his with a digital caliper. He has an '08 Speed 7 with the silver handlebars.