I suggest Matthew continue to use Jacques Offenbach as the composer of
"The Marine's Hymn".  Thomas Holcomb was merely the Marine commandant
who approved the 1942 changed lyrics in one line.  There seems to be
no dispute about who wrote the music.  Since Matthew is only concerned
with the music, he need not bother with the lyricist.

Nevertheless, I cannot explain why my copy of the 1942 sheet music
shows "L. Z. Phillips" as both the composer and lyricist.  According
to the Wikipedia article on the subject, there are three sets of lyrics
to "The Marine's Hymn": prior to 1929, 1929, and 1942.  The article
does not mention L. Z. Phillips.  My 1929 edition has no composer
credits.  It simply says "arranged by A. Tregina, U.S. Marine Band".

Gary Watkins
So. California