I. Outside the Venue: True music lovers (like Todd) sometimes line up hours before the doors open in all sorts of weather in order to get near the stage. Even if you're a normal human being with reasonable aspirations of being in the same room as the band you paid to see, you'll often have to stand outside for hours between the doors opening late (no concert I have ever attended ever took place anywhere close to on time) and the freaks who've been there all day getting their recording gear confiscated by the door guys. Then you actually reach the door guys, a pair of surly men who grunt instructions, eye you like they've seen your face on the Megan's Law website, and go through your stuff. Sometimes they also pat your person.
II. Drinks: Even if the doors opened over an hour late, the opening band will still be getting set up, so you'll be left to your own devices inside the venue for quite awhile. The staff will thoughtfully provide erratic lighting and loud bad music by a nameless DJ, so you can't hold a conversation with the people you came in with (if any) or even try to read lips. Therefore, you will resort to the bar. Drinks at any venue with live music are always atrociously expensive and badly watered-down, although not so expensive or watered-down as to prevent you making yourself sick. Here I should note that the architects and interior designers who put together music clubs are more cunning than any other creatures on earth, and they devote all their talents to hiding the restrooms.
III. The Opening Band(s): Eventually, the opening act will get it together enough to start playing, and then the horror really begins. I have seen exactly one opening band that was any good at all*, and that was in Canada, where everything is different. Generally, opening bands come in two varieties: untalented local bands (primarily at indie, punk, and similar shows) and embarrassments sent along by the record company (at arena-sized rock and pop shows.) In the former category, the most notably bad band I have seen is Antony and the Johnsons (at the Knitting Factory, opening for one of those interchangeable World Serpent related bands) who not only sucked, but added a level of almost Goya-like grotesqueness by having the lead singer perform in worn-out shoes from which his repugnant, pudgy toes protruded. In the latter category, honors go to Nashville Pussy opening for Marilyn Manson (please understand that this was a long time ago and I was young) - a combo clearly put together by some suit whose only understanding of either act was loosely coagulated in the term 'shock value'.
IV. Waiting: If you survive the opening act, you'll have to wait for them to break down and the headliners to set up. See Part II: Drinks. This factor increases exponentially with any additional opening bands which may be in the lineup.
V. Encores: The headlining band may or may not be good, depending on a number of factors, but even assuming they're brilliant, eventually you will want to leave. For one thing, there's no place to sit down at most concerts. For another thing, they're often late at night, and you get tired. For a third thing, see Part II. Anyway, after eight or ten songs you'll be feeling like it's a good time to go, and so will the band. So they'll wrap it up, and everyone will be happy, except for a few insane morons who will start clapping rhythmically. Then more and more insane morons will join in. Then the band will come out and do an encore, which used to be one special song thrown in occasional as a treat for a particularly enthusiastic audience, but is now two or three songs long and obligatory, even if the venue is burning down.
VI. The People: Actually, you'll have to deal with them all through the performance, but I've saved them til last because they're the worst part. A typical example: One night at the Knitting Factory, a large girl came up to me, pointed at her chest (her shirt had a crane on it at about that point) and said, "Turkey."
"What?" said I.
"It's a turkey," she said.
"No, I think it's a crane," I replied.
"It's a turkey," she said, and walked away. My best guess is that I was spacing out in her general direction and she thought I was staring at her tits, but who knows? The point being, I'm too autistic as it is without having to cope with this kind of thing. And that's why I hate going to concerts.
*They were called Two Minute Miracle and they opened for Mercury Rev.