Listen to a Sequence in The On-Line Encyclopedia of Integer Sequences

Usually accept the default settings, but in the Midi player set the tempo almost as high as it will go.

If the midi file won't play (QuickTime always complains in my browser),
save the midi file to your computer, and open it with (say) QuickTime Player.

Suggestions for other examples will be welcomed - send them to Neil Sloane, njasloane@gmail.com.