Festivity Level 1: Your guests are chatting amiably with each other, admiring your Christmas-tree ornaments, singing carols around the upright piano, sipping at their drinks and nibbling hors doeuvres.

Festivity Level 2: Your guests are talking loudly — sometimes to each other, and sometimes to nobody at all, rearranging your Christmas-tree ornaments, singing I Gotta Be Me around the upright piano, gulping their drinks and wolfing down hors doeuvres.

Festivity Level 3: Your guests are arguing violently with inanimate objects, singing I cant get no satisfaction, gulping down other peoples drinks, wolfing down Christmas tree ornaments and placing hors doeuvres in the upright piano to see what happens when the little hammers strike.

Festivity Level 4: Your guests, hors doeuvres smeared all over their naked bodies are performing a ritual dance around the burning Christmas tree. The piano is missing.

You want to keep your party somewhere around level 3, unless you rent your home and own firearms, in which case you can go to level 4.