Adjectives describe nouns (and noun-phrases).
Attributive adjectives precede the nouns.
We can use any number of attributive adjectives before the nouns; hence the term 'multiple attributive adjectives'.
What should be the order or sequence of multiple attributives adjectives?
Formula: OSQ ShAC NMTP.E.g. Accordion is a portable musical instrument.
O = Opinion (adjectives which express opinions e.g. good, bad, etc.).
S = Size (big, small etc.).
Q = Quantity (physical quantity).
Sh = Shape.
A = Age.
C = Color.
N = Number.
M = Material.
T = Type.
P = Purpose.
This sentence follows the sequence of 'TP'.
Portable - an adjective of type.
Musical - is the adjective of purpose.
Let us rewrite the sentence:
Accordion is a musical portable instrument.
This cannot be wrong, theoretically, but the order looks awkward, because it is not in use.
*I am unable to trace the authority for this principle/practice.
*I shall try to quote the authority here, as soon as I am able to trace.
*Using this principle improves clarity of the sentence.
*Dividing line between different types of adjectives, can sometimes be, thin.