As someone who sings a lot of music (nowadays mainly in the shower), I end up singing a lot of music that's outside my range for at least a few notes (or outside my most comfortable range in several notes). By "outside my range", I mean I cannot hear myself sing the note at all, and by "outside my most comfortable range", I mean it takes me more effort to sing the notes (such as the C that's 2 octaves above Middle C).

Whenever the song gets out of my (most comfortable) range, I transpose the section an octave (up or down as necessary). In general, I do not prefer transposing what I sing--it's more difficult to remember that way, and in classical music, the key of the piece is often in the title (such as Mozart's "Symphony No. 40 in G Minor") and therefore looks bad in transposed versions.

As someone who sings a lot of music (nowadays mainly in the shower), I end up singing a lot of music that's outside my range for at least a few notes (or outside my most comfortable range in several notes). By "outside my range", I mean I cannot hear myself sing the note at all, and by "outside my most comfortable range", I mean it takes me more effort to sing the notes (such as the C that's 2 octaves above Middle C).

Whenever the song gets out of my (most comfortable) range, I transpose the section an octave (up or down as necessary). In general, I do not prefer transposing what I sing into different keys--it's more difficult to remember that way, and in classical music, the key of the piece is often in the title (such as Mozart's "Symphony No. 40 in G Minor") and therefore looks bad in transposed versions.