As Mary suggests, the Midi Explorer engine is the one I use 95% of the time. I use the version at http://www.cs.ruu.nl/pub/MIDI/MIRRORS/SMF/help/midi-search.html which also has another 10 or so extra engines if ever you need to find a really difficult one. MIDI Explorer is ruthlessly efficient - typically if it doesn't yield a result you can consider your file as almost unfindable by use of a search robot.

Some time ago somone requested if a Mudcatter could find a MIDI of The Road Runner Theme. I never did find one, but I might try 'meepmeep' in a couple of minutes.

Regards, John