I am attempting to make a new template with wide margins and things are messing up a lot. But now from another post somebody mentioned frame chains. I see the template I have made had name MJ not MA. Where does this come from, what is it? Why J and not B, for example? This could be the source of my woes.
Sorry to clog the forum with so many questions around this.
Itās randomly(?) assigned by Dorico!
You should be able to manually change it back to MA using the frame chain dropdown. MA is always the main frame chain.
Unless you have separate music you want displayed in different areas of your score, you should set all frames to MA. (Although this most likely would be done with Local frame chains.) This will make sure your āoneā music will flow from one frame to another in a logical manner.
Anthony has a good overview of frame chains here:
I didnāt do anything explicit and MJ just appeared, and seems to be messing things up, but this is an area of Dorico I have never used and donāt understand. All I did was attempt to create a new page template. Assigned randomly - you have to be kidding! I think thatās totally bizzare. Am I the only one ever to be bamboozled by this?
Iām watching the videos on music frames!
I believe the āJā is just a sequentially assigned letter indicating Doricoās internal tracking of changes made during the creation process (in the background) that you as a user was involved with. [A little guessing here on my part.] The important thing is the āMā which means MASTER - allowing the flow of your music, and not something that is mainly for display. For instance, an incipit that requires a āLā to display some music locally.
Itās certainly not random. The suffixes are assigned sequentially.
If you create two text frames, then create a custom music frame, it will have a suffix of D.
MA - music frame master
(text)B - text frame
(text)C - text frame
MD - custom music frame
The reason itās confusing, in part, is because text frames are a bit simpler, and they donāt display any identifying labels. But they still have them internally. As far as I can tell.
The standard flow of music goes through the default frame chain. Normally thatās MA, but fundamentally itās āwhatever the frame chain is on the Default page templateā.
If you want a custom page template to be part of the normal music daisy chain, make sure its music frames are assigned to the same frame chain as the Default page template. Creating a new page template ābased onā the Default template should do this automatically.
The Default page templateās frame chain is what determines what gets shown automatically: for example, if youāve got an extra flow in the project whose sole purpose is to demonstrate notation styles in the front matter, but otherwise has no musical function, you want to remove that flow from the Default frame chain. If you donāt, it will appear at the end of the layout (or wherever that flow is positioned in the flow order for the project).
So where did J come from after A? I still bamboozled.
And, the good news is that selecting MA solved all my weird template issues.
J?
thisā¦
I donāt have anywhere near the number of test frames that would push it to J.
Thereās something odd about my project.
Unlikely ā there are a number of text frames already in play in a standard project: for the title, the composerā¦
Itās really not something I would encourage anyone to lose sleep over.
I have no idea where it comes from, but J seems always to be the letter of choice to succeed A when I create new frames, so I just have learned to accept that everything is working as planned.
@Derrek interesting! So itās not me going crazy.
Nope.
Letās count:
Music frame (A)
Left page number (B)
Right page number (C)
Title frame (D)
Composer frame (E)
Lyricist frame (F)
Copyright frame (G)
Header frame (H)
Flow Heading frame (I)
Next one : your erroneously created music frame (if I understand correctly) (J) !
Considering that text frames have no label to identify them as āBā, ā Cā or āDā etc, it does seem strange that the naming convention for Music frames should take them into account, if indeed this is how it works. In a new project, if I insert a new page and insert a music frame, itās called LA1, although there is the option to select MA1. I certainly donāt lose any sleep over it, though!
LA is a Layout frame, something that you create by the means of an override, directly on the page, through Engrave mode frame sub-mode. We are talking about Master page frames here (former name of Page templates framesā¦ or is it Main music frames?)
@MarcLarcher thank you for your explanation but this is nowhere near being obvious or intuitive (a word that I donāt like in relation to software, but perhaps appropriate here). Itās not at all clear that J follows A, and besides, why should the sequence be in the same ānamespaceā? Worse, it caused me more than a day of bamboozlement and mucking up my score, and itās not exactly made explicit in the manual. Me no like! All this trouble and stress just to change page margins temporarily. I think Dorico could refine this behaviour, or have a full explanation in the manual. Reading the manual certainly didnāt reveal this to me.
No, itās not! 
hence Lillieās words! Itās been like this since the very beginning of Dorico, and honestly, probably complicated to change for a very very very little benefit for us users. Just accept it and move on. And thank you for making me look into it, I feel I now why J.
Yes this is one of those things thatās really hard when you first encounter it, and once you know it, it becomes trivial! Lifeās like that.
Thanks for everyoneās help on this.