Hey I'm new here so forgive me if a thread like this was already posted. Anyways I've been wondering is there somewhere online to find transition or the stock music used in sitcoms?

For example here's a short youtube video of an example from George Lopez

http://www.youtube.com/watch?v=oHcKBISg724&feature=related

The music I'm talking about plays at 6 seconds in. Where would I find music like that? thanks in advance!