I am searching for some songs about musical instruments.
I've found:
-Mike Smith's "Hobo's Mandolin" [a.k.a. "This Here Mandolin"]
-Jerry Faires' "D-18 Song (Thank You, Mr. Martin)"
-Gary Fjellgaard's "Me & Martin"
-Johnny Cash's "When Papa Played The Dobro"
-Loudon Wainwright III's "The Ukulele Song"
I'm sure there must be hundreds more.

[Many song titles in this thread have been converted to links by a Mudelf.]