The second part..

where to sing it......one of the reasons I want to address this is because this is a not uncommon scenario - a singer will say when I ask them what they have - "well, I just started working on Zerbinetta two days ago but I could sing some of that". That's a bit of an exaggeration, but the point is you have to know where you can sing certain things. An aria that you are just getting off the ground is not what you should sing in an audition, unless you are asked specifically to work something up, and the auditioner then knows what to expect. Obviously, trying out something brand new for a goup of trusted colleagues, friends, or family is a great idea, but not an audition that will leave a lasting impression as a snapshot of you. Knowing where to sing certain repertoire not only shows your voice in a good light, it shows good judgement on your part, which is one of the "sub-auditons" that is happening when you sing for an opera company or program. More on that point later.....