What is the best quick warm up?

What happens when you show up for an audition early all warmed up and ready to sing only to find out that the auditions are running an hour behind and there are no warm up rooms available?   First of all, don’t panic!  You can always find either a stairwell or a bathroom to be a great substitute for a warm up room but what if the substitute space is too close to where the auditions are being held and it will be way too loud to sing full voice?  We advocate the use of the lip trill to warm your voice up with out blasting away in full voice.  Buzzing or trilling your lips also takes a lot of breath support so you will get a chance to warm up your breath.  Start on a pitch that is in the middle of your range and sing into the buzz coming down in a 5 note scale or a full octave arpeggio.  Then go up a half step and come down again until you have reached the top of your range.  Then go back down a half step at a time until you reach the bottom of your range.  Once you have done this simple warm up, you will be all set to sing your audition.  We start our students on this warm up ever lesson so we totally believe in it’s effectiveness.