text categories in scores (was: Changing midi-tempo within score)

[Noeck]

Hi Simon, all,

next to the notes, there are usually these kinds of texts:

1 tempo: bold, above the staff
2 dynamics: in italics, below the staff (depends on the instrument etc.)
3 articlulation
4 other

Examples:
1 Allegro, Tempo I, …
2 dolce, dim., cresc., …
3 dolce, staccato, …
4 m.d., simile, …

As mentioned in this thread, some tempo-related expressions are often
written in a different category from what would be logical:
rit. accel. a tempo written like category-2-expressions.

a) Why is that the case? Is there a historical reason for that?

b) Would you recommend to stick to this (rit = category 2) or would you
recommend to separate tempo from other categories?

c) Are there correct/scientific categories and terms for these categries
close to mine above (1-4)?

Cheers,
Joram