Thanks for the welcome.

Well I actually followed the advice which was given earlier to the original poster of the question, and sent an inquiry to the company that runs the Heathrow express.

Three or fours days later I got a very polite reply telling me that the music had all come from one album called "Earth Grooves"

The gentleman provided a youtube link with his reply.  Very nice and I now find a whole bunch of interesting videos connected to this.

So job done! cheers. Pete

I don't know if anyone will pick this up.  I was interested in this topic because there was another piece of music that I used to hear while traveling the Heathrow Express around 2005/2007.   That piece of music accompanied a video which showed a lot of speeded up
time lapse photography from different parts of the world.

Does anyone happen to know what the piece of music was or how I could find out?

Thanks in advance

Peter