A lot of these have already been mentioned but when the coffee table is littered with picks, sets of strings in their boxes, electronic tuners, capos, CDs and printouts or hastily scribbled songs in tab form.

Tripping over guitar stands in the dark.

Tripping over cords in plain sight.

The stereo system is better than average with elaborate speakers so every nuance is squeezed out of the music playing on it.

Home computers have music/recording software even if you rarely use it.

One room has a large amp or two.

Furniture supposed to be for your comfort instead comforts a musical instrument or its case.

Instead of porn on your computer, you have thousands of pix of guitars and masturbate to them instead. Your browser address bar has every instrument manufacturers' website stored or bookmarked. If they were as illegal as kiddie porn, you'd be in huge trouble.

You have everything from the Archies to Messiaen to Jimmie Rodgers to Charlie Patton to John Coltrane to the folk music of the Song Dynasty--on vinyl.

When you work OT, you're fantasizing about what instrument or gear you're going to buy with the extra money.

Your couch and the floor next to the bed are littered with dusty, musty past copies of "Acoustic Guitar" "Bass Player" "Modern Drummer" "Mix" and the like. Large color photos of beautiful, state-of-the-art recording studios give you a hard-on (or the female equivalent--whatever that might be). You'd be perfectly happy to move in and live there.

You know something about mikes and recording and know what "phantom power" and "compression" mean and probably have at least a small studio somewhere in your house.

When someone at work mentions having bought a guitar, you want to know exactly which make and model and when they're going to bring it in (I've taken all my guitars to work at some point).

Your main email address is musically oriented.

Anytime you find yourself doling out a large amount of money for a bill or car repair or whatever, you think, "Damn, man, I could have bought that sweet Washburn I saw the other day with that money! Sonofabitch!!!"

You have music oriented wallpaper--computer or house, doesn't matter.