Misc: In 1977 Final European scheduled run of the ---------- (94 years).?

Questions

What British duo's works are referred to as the savoy operas?

what british glitter rocker plays on iggy pop's raw power album?

what british theatrical rocker's alter ego was the thin white duke?

what broadway production of gilbert & sullivan's did linda ronstadt star in the 80's?

what brother & sister duo produced a show in their family studio?