[What became of the Tubular Bells?]

No, it was The Exorcist.

[What became of the Tubular Bells?]

If only it was just a song. Since he released the original album Tubular Bells in 1973, Mr Oldfield has seen fit to offer us Tubular Bells II and III, The Millennium Bell, Orchestral Tubular Bells, Tubular Bells 2003, The Best Of Tubular Bells and The Complete Tubular Bells.

For some reason the phrases 'milking it dry' and 'one trick pony' have just popped into my head.

[depeche mode]

Given David Gahan's past I'd have to guess 'drugs'.

[A song called Ambrose from somewhere in the 1960`s]

I refer the honourable (sorry, honorable) lady to my previous answer. The record in question is almost certainly "Ambrose (Part 5)" by Linda Laurie, a minor chart hit in 1959. Bizarrely, there were no parts 1 to 4.

[Girlfriend - Robbie Riviera]

I've never actually heard it but I believe the song you're after is "Girlfriend" by Robbie Rivera featuring the vocal talents of one Justine Suissa.