with the exception of the half/whole step transition near the end of the song. Modulations that jump more than a major 2nd can be rather odd sounding and near impossible for a lot of singers. Of course one with good range could make a modulation of a 5th.
I can't think of any pop songs that modulate more than a M2. Do you have something in mind? I think the most common are probably tonic-sub dominant, or tonic=dominant, (1-4, 1-5) these have the most home notes between them and are an easy transition, tonic-supertonic (1-2) can work, but tend to sound a little lame on their own, usually they keep modulating till you hit 4 or 5. 'Fishstory' has the right answer, especially in relation to vocal music. It would be very difficult indeed for a singer to be able to move an interval up more than a third, unless they have a 4-octave range. | 