While watching the start of Panorama this evening it occurred to me that the theme hadn't changed as far as I could recall. A quick bit of googling turned up this site:

Link: TV Theme Music and Songs - TelevisionTunes.com

Browse our huge archive of 26,489 theme songs.

If you can't find a theme song, contact me and I'll try to get it for you.
Listening to "Panorama - TV of the 50s Version Theme Song" shows how similar the current theme is to that from the 1950's.