I want to sing a song performed by a soprano/mezzo-soprano

[Unvoiced_Apollo]

But I'm a baritone. Anyone have any idea how many keys I should ask the music to be lowered? The song is in A major flat if that matters.

[Gendo]

Really depends on both your range and the range of the song. It's possible that you can just go a full octive lower, in which case they wouldn't actually need to transpose the music or anything.

So says my wife, a music teacher.