Well, a social media post on November 24 suggests that there's some trouble going on in Mangini's mind:
"Happy Thanksgiving USA ! I'm focussing on gratitude and trying to block out all other thoughts (even though it is tough to) with song parts and one's own thoughts on all kinds of things looping in the mind."
Then a rather tired post on November 27:
"I don't remember ever flying on a Sunday after Thanksgiving 😡I cant stand missing an NFL day 😡😡 Weather is good though 😁."
Subsequent posts, however, seemed to portray a better state of mind, with him focused on learning songs for the Images and Words tour:
November 28: "Show tomorrow night.
I'm continuing to study (but not play) songs in the "time cracks" of life. I like to classify what I experience as a "medium term" memory where I can layer audio and images in my mind. i.e. I can hear my own voice saying, "4,4,3" while I hear a song in the key and time of the original. This then transfers to the stage while I'm playing, hearing those memories and hearing the sounds of my environment. I do the same with images. I might see my handwriting, or music notation and other things sort of visually layered. I like to imagine giant numbers too, like a 1,2 & 3, to count verses for example. A lot of it only lasts limited months though. Still, I believe this is a learned skill just by believing you can and then working at it. If you see me giggling on stage, it sometimes means I've gone back in time to something funny about my experience with that song. Too bad an electrode isn't hooked up to my brain and projected on a show screen. ? Well, maybe we're all better off that nobody invented that yet."
November 30: "Here's more info on song learning: I use a written "shape" form that looks like a big grid with blocks, meaning it has headings (Intro, Riff 1, Verse, Pre Chorus, Chorus,) on the left the rows are numbered (1,2,3...) maybe 3A, 3B too, and the number of bars fill in the grid.
That works insanely well for more normal song forms. Also, this form fits on a small square of paper. That worked with Another Day when I had to learn it a day or two on the road with no drum practice, but perform it one time. I taped that to my mini snare.
With most DT songs, I have to expand the amount of rows and change headings because things don't repeat. It takes two pages sometimes, so I have to mentally picture/think of one song as three songs. One example I remember is Dark Eternal Night. I'll write 6 5 6 5(>3) 6 5 6 15(555) when the crazy part starts on a separate piece of paper. I'll use numbers like that so that I know that the last 5 on part 1 accents every 3 16ths and the 15 means there are three groups of 5/16. Later, I wrote 20 to mean four groups of 5/16. Seeing a 15, then a 20 is easier for mind to photographically remember as meaning to play 3 5's on one phrase and 4 5's on the last phrase."
December 4: "More on song learning with a different spin: Just a thought here on how music transcends barriers and it is a truly amazing and great thing. As today is an off day, I am reading a lot as a way to self-educate on whatever subject I'm choosing today. I'm finding the understanding of the 'word,' and narrative/argumentation/ rhetoric etc. is almost the most important thing; a priori of sorts. Otherwise, understanding different views is more difficult due to emotions ruining how we reason. My understanding as a teacher of what it took to open up a musician to styles other than his/her own led to my really valuing how to make connections between seemingly unrelated things. i.e. picturing block forms of song outlines is the same thing as picturing outlines on any subject for school tests, or for memorizing sports game plans. Having a good "pitch" was part of it too. That's where making a good case with verifiable truths or at least some good proofs comes in handy. Like all (or most) of you, and most people most likely, we have so little time to ourselves on the road and so much to do in just keeping up our chops as a prerequisite for our jobs. There's no time for 'lazy.' A good benefit is how non-musical learning can morph back to the instrument. i.e. Seeing good cases made for things reminds me to not put too many ideas into one drum solo, or one drum fill etc."
On December 6, he retweeted the Dream Theater post: Thank you to our crew for all of their hard work in making The Astonishing Live show happen night after night."
Then earlier today: "I'm home! On to actually getting on the kit to learn the 2017 tour songs. Converting what's on paper to my kit is pretty weird, but FUN!"
My guess what's really happening now with Mangini? He's tired.