When checking out some Google returns on the history of UK broadcasting (occasioned by another thread here which mentioned Sir Arthur Bliss), I came across this URL:
http://www.testcardcircle.org.uk/ITVDISCO3.HTML#one
The Test Card Circle (a group I've known about for about twenty years) is as anorakish about the history of television test cards and the music played out with them as we are about The Shadows - and more power to their elbows!
I was particularly drawn to their list(s) of commercial LPs played out over the test card during the 1960s. A half-forgotten memory reminded me that I often heard The Shadows during the ITA's test-card transmissions on weekday afternoons the summer of 1964 (when I had just acquired my first reel-to-reel tape-recorder...). And sure enough, there is "The Shadows' Greatest Hits - Columbia 33SX 1522" listed as having been played (effectively five times a week, both sides) between March and September 1964.
Where do people get this data from?
JN