Yup! You just said it. Opening music. Some other names are themes, theme tracks, theme music, opening theme, theme music and way more! ;D
The original music by Patrick Doyle. The theme music is not specified in the ending credits.
LA Law
According to the opening credits, Mike Post and Pete Carpenter co-wrote the theme song...
Billy Joel
The theme music on "The Walking Dead" is called "The Walking Dead Theme" composed by Bear McCreary. McCreary is also responsible for the theme music for "Battlestar Galactica" and "Da Vinci's Demons."
Go to Ear-tweak.com and select 'The Music' to see all the opening and ending theme songs used in the show. (If you look closely enough during the credits [somewhere in the beginning I guess] you should see Ending Theme and underneath it will be the name of the song playing).
My guess is that they eliminated the opening theme song for one or two reasons. First, and most likely, is that playing the theme would require them to pay performance royalties (separate from the copyrights on the actual show). Second guess is that the opening has been shortened slightly to fit more commercials, but the music track could not be edited to accommodate that change.
Try youtube.
a different version of the hyrule field/twilight princess theme
This is not actually a full size song but a normal Show Theme / Opening music.
It isa great (closing)theme song - the only place that I can find it (the longest version of it that is) is on youtube, the end of the very first episode in 1968. I would love to get the sheet music for it and learn it on the piano.