Party - Freddie (chiefly), with Brian and John
Khashoggi's - Freddie (probably), although lyrics could've been by all four
Miracle - Freddie on music (some help by John in the beginning), all four on lyrics
I Want It All - Brian
Breakthru - Intro by Fred, rest by Rog
Invisible Man - Roger
Rain Must Fall - John, lyrics by Freddie
Scandal - Brian (chiefly, at least)
My Baby Does Me - Freddie and partly John
Was It All Worth It - Freddie (music), and lyrics by all four
Innuendo - Freddie (music, after an idea by the other three), lyrics by Freddie and Roger
Slightly Mad - Freddie (lyrics by Freddie & Peter Straker)
Headlong - Brian
I Can't Live With You - Brian, originally called 'I Can't Live Without You'
Don't Try So Hard - Freddie
Ride the Wild Wind - Roger
All God's People - Freddie (credited to Queen/Moran but registered as Deacon/May/Mercury/Taylor)
Days of Our Lives - Roger
The Hitman - Freddie
Bijou - Freddie (guitar parts) and Brian (vocal parts). Yes, it's Freddie (guitar parts) and Brian (vocal parts), I didn't mix them up.
Show Must Go On - Brian (after an idea by Roger and John and with some minor lyrical contributions by Freddie)
Beautiful Day - Freddie
Winter's Tale - Freddie
You Don't Fool Me - Freddie & Roger
I suppose the version you've got isn't actually Brian singing the song, but Brian singing one minute of the song (ca 25%), which doesn't necessarily mean he wrote the two verses he's singing there, let alone the rest of the track.
But I admit that one's always been a coloured area (not even grey). It wouldn't be the first time that Fred wrote a heavy thing, but otoh it would definitely be the first time Bri sings all backing vocals in a song by Mercury (which still doesn't mean it's impossible).
Comments from people involved were vague: in one interview, Dr May (Sunset Strip, 1991) said that Fred had composed most of the riff, Brian wasn't even in the room back then, but then he took the song under his wing, and the finished version had very little to do with the original one. If so (and overlooking what he said about John organising the structure, which enters in the 'arrangement' area IMO), then it could, for some extent, be a similar case as Rog writing 'Ga Ga' after what his toddler son said.
Another interview (coming from 1991 as well) has Brian saying that it had mixed approaches or something like that, and he didn't actually credit it to anybody.
In late 2001, producer David Richards said he'd got two different memories: one of Brian writing it, and one of Freddie doing so.
Thus, it's still a complicated matter. It's definitely NOT 100% by either.
Cambridge Dictionary defines 'song' as:
"A usually short piece of music with words which are sung"
And it defines 'music' as:
"A pattern of sounds made by musical instruments, singing or computers, or a combination of these, intended to give pleasure to people listening to it"
So... as long as YDFM had words and melody, it was already a song, before Freddie died.
Sebastian....I noticed you left 'Delilah' out of the track-listing for 'Innuendo'.
It's never been on any of my homemade cassettes or CDr's as well. Doubt Roger's ever given it a listen since '91 as well.
"Another interview (coming from 1991 as well) has Brian saying that it had mixed approaches or something like that, and he didn't actually credit it to anybody."
I never heard that interview, but this has always been my theory on the song. And that would also explain why Brian sings that peticular demo. Brian did his approach of the idea Freddie had, and sang it to explain his idea to the rest of the gang