A little correction, Gilmour just came up with the four note "Syd's theme", not the whole SOYCD musical theme. "Guitar theme" makes it sound like that, and gives the wrong impression that he wrote the whole thing. But just like you said, other than that there is no real evidence on who really wrote what melody part...Hudini wrote:Music for SOYCD was written collectively by Waters, Gilmour and Wright, where it was Gilmour who came up with the guitar theme.
I also read somewhere a long time ago, don't remember where, that Roger came up with the song and the lyrics and Gilmour then wrote the famous guitar intro, not the whole melody and chords. Someone can confirm the source for that?Again, music for WYWH was written by Gilmour and the whole thing just screams "Gilmour" all the way through. The song does feature lyrics which objectively rank among Waters' finest, but that does not earn him an extra credit for composition.
As for Waters having no musical talent or ear for melody... has anyone actually listened to the Wall demos? All the melodies were already there. What Gilmour and Writght put into the mix, at least on that album, was great arrangement and top notch solos. And I think 2 or 3 demos for songs. Of course there's no way to tell exactly who wrote what on the albums before that, but this whole myth that Waters was just the lyricist and conceptualist is totally ridiculous, the guy also wrote a lot of songs, which means he came with the guitar chords and vocal melodies for them, not just the lyrics. People get confused when he is referred as the "principal songwriter" and believe "songwriter" equals "just the lyrics". It does not.
There's a reason why Gilmour and Wright solo albums from the 70s suck, and it's not just the awful lyrics. The songs lack structure, musical tension and craft. Those three guys need each other as much as... I don't know... I'm not good at metaphore.