[Former Member 443]

I can't fathom out though why Grampian kept on using the ident music for the best part of a decade. 

I'm sure they used their own ITV ident well into the mid 90s as well.

The ident music of course (which though unusual, was very nice) was kept on by a number of regions - aside from Grampian, LWT, Tyne Tees, and Border used either the original version or rearrangements well into the 1990s.

The ITV National Weather also used it, first the original version, and then a series of weather themed rearrangements (the so called “Weathergens” because Powergen were the sponsor at the time) that continued well into the 1990s till they were replaced with a second set of Weathergens with different music.

Edit: the name “Weathergens” may have strictly speaking referred only to the second set, that didn’t feature the 1989 music. Powergen was the sponsor throughout this time though.

I wouldn't say "well into" in TT's case, the replacement ident that reused the jingle ran for less than 18 months and was gone in 1992, at which point five ITV companies were still using the original version (or a minor variation thereof). 

I believe in TT's case, the decision to reuse the music was pragmatic in any case - the 1991 ident apparently was a rejected package from the late 1980s (note how close it is to the 1988 Northern Life intro) which happened to (almost) match the ITV jingle (it is in fact about half a second out of sync with the final form-up) that allowed them to rebrand on the cheap - they were actually the first company who had taken on the 1989 package in full, to drop it, again after around 18 months. Management were never keen and just wanted it gone.

People often forget in this that YTV did use what amounted to the original package until 1994.