UnScramble this Word: d a m y d o r r e?

Questions

Contains: Zip-a-dee-doo-dah.?

Have yourself a merry little christmas, The boy next door, Trolley song.?

I'm glad I'm not young anymore, I remember it well, Thank heaven 4 little girls?

Kopit-Yeston musical which was often confused with a Lloyd Webber one?

Musician in each of: Bad Company, King Crimson?