Zippel's first work with Andrew was actually 17 years ago in 2004 with WOMAN IN WHITE.
I can't really fault Don' Black's work with him on TELL ME ON A SUNDAY which is a bit of a classic here in the UK and was written as a solo album for Marti Webb, not a show. Its crazy success leading to SONG & DANCE was entirely a fluke. As for Richard Stilgoe, STARLIGHT EXPRESS is hardly GYPSY but it was never intended to be taken too seriously given that it is basically a child's imagination come to life. There is some fun stuff there though admittedly not everything lands.