However, it should be possible to use the same templates for portrait and landscape, as long as the constraints (the padlock things) are set correctly on all the frames, so that the frames position themselves on both page types in the desired way. (And assuming you want the same frames and text in each…)
mmm still can’t find it what I need…
Success: I have one layout in Portrait, one layout in Landscape
Failure: I made a new ‘template set’ but I can’t figure out how to define ‘template set A’ should be Portrait and ‘template set B’ should be Landscape
Whether or not pages in a layout are portrait or landscape depends on the layout, not the page template. Essentially, page templates define “arrangements of frames” to “stamp” onto pages.
In a layout set to landscape orientation, you’ll see landscape page templates. In a layout set to portrait orientation, you’ll see portrait page templates.
In theory, and as Ben said earlier, you should be able to use the same page templates in both portrait and landscape layouts, provided your frames have the right constraints set. E.g. the text frames have unlocked bottom constraints, so they maintain a fixed height rather than covering say 15% of the height of the page, however high that is; and music frames have locked constraints on all sides, so their height and width both adjust according to the size of the page, and they always fill most of the page (to fit more music on).