What’s the theme music on the McVities biscuit adverts with the kittens and puppies?

What TV shows is the music from in the 2014 McVities biscuit adverts with the little kittens and puppies coming out of the packets?

The ad above with the kittens for McVities milk chocolate digestives features the theme music from ‘Fawlty Towers’ and the ad below with the puppies for original digestives uses the song from ‘Murder, She Wrote’.

I believe the breed of dogs used in the advert are Corgis and the cats are British Shorthair kittens.

Fawlty Towers is a classic BBC sitcom from the 1970’s which was written by and starred John Cleese and Connie Booth. Despite its popularity, there were only 12 episodes ever made.

Murder, She Wrote was a US mystery series which starred Angela Lansbury as writer and amateur detective, Jessica Fletcher. The series originally ran during the 80’s and 90’s, with over 260 episodes made.