Law & Order ends its 20 year run tonight. To put that in perspective, here's a quick snapshot from the beginning and end of the series' lifespan:

'Law & Order' Goes Out on a Oddly Personal Note

The procedural series' finale can't totally resist the urge to get series finale-y, giving us an emotional scene of Lt. Anita van Buren coping with a disease.

While van Buren's name may remind us of L&O's long-standing tradition of giving their police officers awesome porn names (Det. Lennie Briscoe, Det. Joe Fontana) it breaks L&O's cardinal rule: "never pretend anyone gives a shit about these characters."

However, we'll always remember the good time thanks to the series' twisty episode length story arcs, and the fact that it has been on at least one cable channel constantly for the past 12 years.

Theme Song

The thing we'll probably miss the most is the theme song.

Law & Order's "dum-DUMMM" are inarguably the most recognizable two notes in TV music history. The only show to ever challenge its supremacy, '24' (Beep- Boop, Beep-Boop, Beep-Boop) also airs its final episode tonight.

Unlike '24', the 'Law & Order' theme and writing staff had the professional courtesy to not just keep hitting those same two notes over and over until you felt like you were in some sort of migraine induced time loop.

Here's a clip of Will Arnett playing air guitar to the funky jazz guitar riff that filled out the remainder of the them song. Yes, the 'Law & Order' is so old, the theme song was played on something called a jazz guitar.