Song title capping convention in English is to uppercase every word in the song title. Check out any songbook, music book, or piece of sheet music to see examples. Case closed.

I will re-open the case just briefly. Before me I have the sheet music for "I Wonder Who's Kissing Her Now" (Howard-Hough-Adams), from the film of the same name. There is a sidebar listing other songs from the same film as "Be Sweet to Me Kid" and "What's the Use of Dreaming", both written thusly.

So the 'every word capitalized' seems to be a convention of the sheet music publishing industry and not the general rule for song titles, which is the same as for other titles.

In this box there are about 100 pieces of sheet music. I did a very rough approximation and it looks as if about 45%, give or take, of the titles are in caps and l.c. with EVERY word capitalized, 50% are in ALL CAPS, and the remaining 5% or so are 'mavericks'; for example, here is Hazel Scott's piano solo arrangement of 'boogie-woogie', written thus (all lower case). "Candy" (David-Whitney-Kramer) has the title formed from pieces of candy canes.

Some of these songs give new meaning to the term 'oblivion'. Anybody remember "I SAID MY PAJAMAS (And Put On My Pray'rs)" (Pola-Wyle)? How about "A STORY OF TWO CIGARETTES" (Stoner-Jay-Marker)?

Irving Berlin wrote some of the most famous songs in American history. He also wrote tons and tons of absolute crap. Who remembers "YIDDLE ON YOUR FIDDLE"? (That sounds almost obscene!) How about "NEXT TO YOUR MOTHER WHO DO YOU LOVE?"? Anybody remember "KEEP AWAY FROM THE FELLOW WHO OWNS AN AUTOMOBILE", "PULLMAN PORTERS ON PARADE", "HE'S A RAG PICKER", or "COHEN OWES ME $97"?