As a pianist, I find that I am able to transpose common lead sheets fairly easily. Songs I know well, such as Somewhere Over The Rainbow, I can transpose to any key when asked. I have been complimented on my proficiency in this skill. But I don’t understand why. It would seem a natural skill of accompanists to be able to transpose, certainly not for classical pieces that require precise notes that may be more difficult, but for lead sheets where harmony and chords are the main tools for success. When accompanying singers, you have to be able to play in their key. So you must have a good ear for harmonic progressions.
My question is this: Is the ability to transpose songs (within the general Great American Songbook context) something more rare or common when it comes to your average accompanist? I’m seriously not fishing for compliments–I’m just asking if your general, everyday, run-of-the mill accompanist/pianist will reach for that transpose button on his keyboard or be able to transpose it in his or her head?