Check out "Entrance of the Gladiators" (ie, the stereotypical circus song.) It uses all the notes on the chromatic scale, so it doesn't "fit" into a specific k

Check out "Entrance of the Gladiators" (ie, the stereotypical circus song.) It uses all the notes on the chromatic scale, so it doesn't "fit" into a specific key. (But it's still considered to be in a specific key. The notes outside that key are the exception not the rule.)