The Music Grunniens

Question

Clues:

[Contextual image: music notes, two +1 markings]

Instructions:

Name that actor

_ _ _ _ _ _ C _ _ _ _

Answer 1

The missing actor is

HUGH JACKMAN

Let's take the notes on the staff,

convert them to numbers (A=1, etc.), and sum them together when connected by a bar:
D+D=4+4=8=H
G+G+G=7+7+7=21=U
G
E
Ex5=5x5=25=Y
A
E+E+1=5+5+1=11=K
F+F+1=6+6+1=13=M
A
Bx7=2x7=14=N

Which gives

"Huge Yakman" which might be mistaken for our answer which fits the provided blanks: Hugh Jackman!

As for the title,

"Grunniens" is the scientific name for a yak.

OP Addition - In 2021 Hugh Jackman played Harold Hill in The Music Man.