Here's the version that I was first exposed to:
But then, at the beginning of the fourth series, the theme music changed a bit--it added more drums, piano, and bass, giving it more of a "rock music" feel. To be honest, I didn't like it as much. While some comments that I've read say that the fourth series theme matches well with the adventurous nature of the Doctor, I think the added instrumentation takes away from the distinctively eerie quality of the 2005 version of the theme.
All of this also made me wonder: what other changes has the Doctor Who theme music undergone since the show's beginning?
Quite a few, I found out. Here's the original version of the theme, as composed by Ron Grainer and Delia Derbyshire:
Quite frankly, I like this version even more than the 2005 version that I first encountered. The minimalism is fantastic, the eerie quality of the music is even more pronounced, and the electronic effects very clearly mimic some of the noises of the TARDIS--an aspect of the theme that I think gets lost in the newer, more melodic versions of the theme.
Reading up on the development of this theme music was also quite fascinating. Not only is the Doctor Who theme notable for being one of the first electronic music TV themes, but it's also important because it's an early example of electronic music that a woman--Delia Derbyshire--had a key role in creating. The Wikipedia page also talks about the numerous reworkings of the theme that happened, even before the 2005 reboot.
Of course, now there's even another version of the theme--this one from 2010, with Matt Smith as the 11th Doctor.
What do you think? Do you have a favorite? Is this latest version any good, or should they have just left well enough alone?