By " logically valid " I mean here " deductively valid". This is a broad sense of logical validity which requires only one thing : namely, that it is logically impossible for the conclusion to be false in case the premise(s) is/are true.
A classification of logically valid arguments
(1) formally valid ( valid in virtue of its form alone, the meaning of the non-
logical symbols/expressions playing no role in the validity).
(1) A/ truth functionally valid
(2) B/ non truth functionally valid
(2) valid, but not formally ( valid in virtue of the meaning of non logical words).
Of 1 A)
If I think, therefore I am.
Therefore I am.
Of 1 B)
All men are mortal
Socrates is a man
Therefore Socrates is mortal.
Peter is a pianist.
Therefore, Peter is a musician.
The form of this reasoning is
(1) P (a)
(2) Therefore , M(a)
in the context of predicate logic.
The form is
(2) Therefore M
in the context of sentential logic.
Consequently, it is easy to see that the reasoning is not valid in virtue of its form.
It is logically valid however since it is logically impossible fo the conclusion to be false if the premise is true.