Brian May:
"Ah ! The strange key of No-One but You ! - an interesting question indeed.

There are MANY reasons why a recording might not be at "concert pitch". I won't go into them all here and now. But "No-One but You" is a special case. I originally recorded it as a solo track, and it was Roger who paid me the compliment of wanting to bring it under the Queen umbrella. Of course I couldn't refuse, because the subject matter was very much Queen relevant, and the track would reach Queen fans much more effectively if it appeared under "Queen" rather than "Brian May".

But of course as soon as you throw a song into a group arena, you no longer have full control. Queen was always a democracy, and songs were always pulled to pieces in the process of becoming Queen tracks. Almost always they benefited. My solo version of NOBY was more or less complete as regards keys, guitars, and vocals, but I had already asked Roger if he would play drums, as the piece was really "Taylor-Made" (sorry!) for him. Roger felt strongly that my tempo was too slow, and convinced me to try changing the tempo. I was happy with my vocal, but of course changing the speed of my track also changed the pitch. We decided against using the "stretching" technology to return the track to original pitch, since so much quality would have been lost (the machines are better now).

So, unless I wanted to start all over again with my vocal, which I felt had that "First Thought" vibe, I was stuck with it being slightly raised in pitch. I got Roger to sing the middle verse so it would become more a Queen thing, using my track as the demo in this case .... I enjoyed 'producing' his vocal, pushing him to try things ... and Roger played superb drums - he has the ability to make you feel every hit is for a reason, a rare quality. So the track evolved into what you hear on "Queen Rocks". I mixed it, and actually contemplated returning it to the original pitch, but Roger was so convinced it would stop Radio playing the track, I gave in. That's one decision I've always regretted, (Radio pretty much never played it anyway!) but it's water under bridge.... "

Credit: BrianMay.com