I had difficulty finding MIDI files until someone told me to use
a MIDI search engine.  Here's one from Van Basco:

  http://www.vanbasco.com/midisearch.html 

By typing in the phrase "midi search engine" into Google you will be
able to pull up other search engines as well.  While searching for your
favorite tunes you'll end up on many private web sites and can and up
downloading viruses so be aware.  I've collected hundreds of MIDI files
in the past few years.  Some of the arrangements I've run across are
fantastic.

Paul Manganaro