Arguably I should have posted this earlier than I have, but someone may yet find this useful. It's a kind of survival guide to playing the piece, including various things I found that made life easier.

* Notation: If you're not much of a reader, that presents some difficulty, but it's not insurmountable. You're halfway there with your rhythm notation, so I have a suggestion for the pitch half of the equation.

As someone who's played guitar for many years, I tend to think of the guitar as being "in" E, since that's how the lowest and highest strings are usually tuned. As a tenor, though, my guitar was tuned to all B strings (octave unison), which I found to be disorienting during the 2004 sessions--I'd often have to double-check what fret I should be playing by looking at the fretboard, doing a quick recalculation in my head, and playing that note. The problem was, in certain sections there was no time for that, and looking away from the score led one to getting lost quickly.

So this time, I cheated my writing fret numbers for each note above or below the note head, depending on which set of strings the note is played on. (For the thinner strings/higher notes, write above the staff; for the thicker/lower, write below the staff.) To save time, i did this only for "new" notes--for the static sections requiring the same notes over and over, I didn't have to do that much writing. This was my sanity check, so I wouldn't have to keep translating from E to B, and I think it'll help you.

* Getting lost: This happens. Fortunately, if you're watching John conducting, he's doing the following:
1) keeping the beat with his left hand (as I recall). 1 is down, 2 is left, 3 is right--though I may have that reversed, and 4 is up. At the very least, you know where the 1 and the 4 are.
2) with his right hand, he's indicating which bar we're in during the current set of ten bars (this gets a bit tricky above five, but you can follow his system)
3) on any 9th bar, he holds his hands up to remind you that we're coming to a 10th bar
4) on many of these bar changes--5s, 9s, and 10s, he mouths the number of the new bar.

With all that going on, if you're not sure where you are, it's ok to stop playing for a bit, watch John, and look at your score. That way, you can see what's coming up, and get back into the piece at a predictable spot.

I also found that if I got lost, I could keep one eye on John and one on Reg, our section leader. In several sections, I knew what we were supposed to be doing in general, but not necessarily what we were doing right this moment, so keeping an eye on Reg was helpful--as Glenn's wife, she was obviously very involved in the preparation of the piece (according to Glenn, she did all or most of the copying), so I'd figured that she would know what to do. If you're not in Tenor 1, watching her does you no good, but watching your section leader can help. I was also lucky in that from my seat, when I watched John, I could see Reg quite clearly in my peripheral vision. Luck of the draw, but if you're in the front row, that's a benefit. (The problem with being in the front row is that the audience can see you looking at the other players.)

* Score management: Dealing with loose score pages is a nightmare. I was able to do this for the first version of the 13, but this version goes by way too fast for that. The first day was a real struggle, with all those loose sheets flying around. Some people came prepared, with their scores bound at Kinko's or somewhere, which made page turning easy. I ended up taping each movement together in a long sheet, and then folded each accordion-style. This worked fine, although I should have paginated differently--I forget how I was doing it, but my pagination had my page turns occurring one page before/after Reg's page turns, and that occasionally made me think I had lost my place when I hadn't. There's something reassuring about everyone turning pages at the same time.

Bring a pen or a pencil for in-the-moment notations or corrections. If they're still using Encore, they'll still be making corrections.

* Amp: Make sure you have a loud enough amp: 25 or 30 watt output at least, and two 10" or one 12" speaker, at least. A few people had little amps that had to be pushed into distortion in order to be heard, and they sounded awful. If you're using a tube amp and a guitar with older or weaker single-coil pickups, consider adding a preamp to your signal chain. In 2004, by the end, I was running my amp on 10. It didn't blow, happily, because takes were short then, but for a full performance, I'm sure the amp would have suffered. Knowing this, I brought a preamp this past time, and was able to keep my amp at 6 the whole time.

Other people's amps did blow fuses and tubes, so it's a good idea to have spares. I had a spare for each tube in my amp, though I would have been screwed if I'd have blown a fuse.

Guitar: Just make sure everything's stable. You don't want the output jack connections breaking in the middle of the show. Make sure that your double-strumming position is comfortable. If you find that you're continually cutting yourself or whacking your hand against something, the damage is going to accumulate during the rehearsals and performance. Some bridges are ideal for this kind of playing (like the wraparound LP Jr bridge on my old Kalamazoo), but some have a lot of exposed metal sticking up, which you'll have to watch out for, avoid, or put tape on or something.

How's your guitar's intonation? Does it play in tune all the way up the neck? If not, then I'd look into having it properly set up. One can do this oneself (I do). If you like the action of the guitar (proper string height, no buzzes, no dead spots) and the only problem is your intonation, you can adjust this at the bridge: see this link. If you have other issues, like action, neck bow, dead spots, etc., I'd take the guitar to a shop for a setup. The intonation would be different for the octave unison tuning, so you should mention the tuning to the shop. (If they're jerks and give you a hard time about the tuning, go elsewhere. They'd probably do a bad job anyway.)

Strings: I had good luck with GHS strings for these sessions. Very little breakage. Whatever strings you use, it helps to bring a bunch of them for your own use. The community string bag is a helpful fallback, but I found I broke those a lot more easily (Dean Markley). If you're breaking a lot of strings at the bridge or the nut, you might want to lightly take a slot file or nail file to the string slot there to even out burrs or other irregularities. There's a lot of back-and-forth motion for these strings over two/three days, which means the string rubbing over the same contact points again and again. If you're getting consistent breakage of one string in one place, a burr is most likely your problem. Also, when you're changing strings, it helps to draw back and forth through the nut groove with a pencil. That prevents string binding when you're tuning. Some people spend money on graphite nuts; you can get the same effect with a pencil.

I suggest having a complete fresh set to put on immediately after the last pre-show rehearsal. Go into the show with a fresh set of strings (even if there's life left in the ones you have on), and you probably won't break any during the show.

If you have a pocket electronic tuner, bring it. If not, someone around you will have one.

Picks: I used the Clayton .94 mm. Indestructible. As a comparison, I really ground down a conventional pick in the 2004 session: see this photo (Control unused pick on the left, with two post-Branca picks on the right. The middle one only lasted one six-minute take. The Clayton is at the far right--and it's the one I used consistently throughout the 2004 sessions.) Bring a lot of them.

Other necessities: Bring a couple power strips, and mark them as yours. I brought two, and immediately after plugging them in, everyone else around me plugged into them (happily, leaving me with the two slots I needed). I did get them back at the end, and I was glad I brought them. Bring a string winder and wire cutters for quick string changes. Bring an extra guitar cable or two. Any little screwdrivers or hex wrenches you usually use for adjustments to the guitar, bring 'em.

Gig bags are better than cases, unless your guitar is really fragile. I was able to fold my bag up under my chair, and thus had access to my spare strings and tools as I needed them, without having to go offstage for all that.

Food/comfort: If you're vegan, let the organization know before the first day--preferably as early as possible. I assume these days are being catered, or food's being brought somehow. The vegan food is always better than non-vegan, and so non-vegans seem to scarf up the vegan food before the vegans get to it, leaving the vegans with nothing. This was an issue in Montclair. But if you're vegan, get on the list so that they know how many meals to set aside.

I brought a stainless steel vacuum bottle for espresso--I'd buy a quadruple shot in the morning on the way in, put it in the bottle, and then have access to good coffee throughout the day. Good also if you're a tea drinker--it's good to leave a couple of bags of Throat Coat steeping for several hours if you're feeling a cold coming on. Keep a few of your preferred energy bar brand in your bag for that late-afternoon slump.

Conduct: In NJ, some people got a reputation for annoying others by noodling between takes ("Sunshine of Your Love," "Stairway to Heaven," etc....all of them *can* be played in Octave Unison, but should not be), or by not following John's instructions, notably on the very end of the piece, where we have to watch him for the signal to mute our strings on the last downbeat--no continued sustain or anything; we want a blast of absolute silence. During the last rehearsals on the second day, one guy consistently would not stop when John signalled us. Several times, over and over. "Oh, I guess I wasn't paying attention." Don't be that guy. Watch the conductor.

Practicing between rehearsals is fine, as long as you roll off all the volume on your guitar, or do what I did: since my guitar has two volume/tone controls (one pair for each pickup), I used the bridge pickup as my "live" channel on 10, and the neck pickup rolled off to 0 as my practice channel. At the end of a take, I'd flip the switch to the dead channel so that any practicing I did was acoustic. It's fine to practice sections of the score that are giving you trouble. I think that's generally appreciated, but noodling is not.

Oh, and do make an effort to follow the dynamic instructions. There's only p and f, but people really want to play this f all the way through. I think it'll be appreciated if you try to play p where marked.

Misc: Hearing protectors are essential, but you probably knew that.

As for knowing the parts, I would play through them as much as you can. If I had to suggest a private rehearsal regimen, I'd say try to play through one movement a night, which would give you two full playthroughs before the real rehearsals start. Do you have a metronome? It'd help. I'd try your first rehearsals at a slower tempo, and then start upping it. You won't feel very comfortable doing rehearsals on your own, but the time you spend now will pay off when you get to the group rehearsals and the show--things will begin to look familiar, and you'll encounter little oases where you know exactly what to do. Enjoy those sections, and don't worry about the ones that might give you trouble.

I did indeed have a good experience overall, though I did have a bit of a slump on the first day, so don't worry if you feel the same thing. (What am I doing here, this is too hard to play, I'm screwing up, etc.) If you do feel that way, definitely go back for the next day, and you'll likely feel a lot better by the end. It is an ultimately exhilarating experience, I think, and quite enriching.