For most of my performing career, this sentence was on almost every audition breakdown I received and it seems that things haven't changed.
As audition season is well and truly back and many of my students are doing the rounds to get that next job, I'm hearing this more and more.
Now what exactly do they mean by 2 contrasting songs?
It really could be anything from 2 different genres, an uptempo and a ballad, a character song and a love song, a belty number and a softer piece.
There really are so many options, which is why it's always good to bear in mind what the role is that you are auditioning for.
Cruise Ships: more often than not, on cruise ships, you will be singing as little as 5 different styles in the production shows. These can range from Broadway/West End, Pop, Rock, Motown, Classical, Big Band...the list goes on. So it's always good to take 2 different genres to a cruise ship audition. My advice would be a Musical Theatre and a Pop/Rock song, then fine tune those pieces to make sure you have an upbeat and ballad amongst those. They also want to know you can connect to an audience, so make sure you understand the context of your song and really tell that story.
Musical Theatre: depending on what musical it is, I would always suggest choosing a piece that is written by the composers of the show you're auditioning for. An example would be if you were auditioning for 'Les Mis', then taking a song from 'Miss Saigon' or 'Martin Guerre' would be a good choice then select a song from a similar style show but different composers and perhaps with a different tempo.
If you're auditioning for a jukebox musical - 'Mamma Mia', 'We Will Roc You', '& Juliet' - then again look at the writers and what other songs they have penned that don't feature in the show. In the case of 'We Will Rock You', it would be a good shout to look at other rock musicals like 'Rock of Ages' and 'Bat Out f Hell' as they have the same energy and style behind them and they'll be looking for that true rock sound. You could also take a stand alone rock song as your contrasting piece, showing off more of your vocal/acting range.
Most importantly, make sure you understand the story and character you are portraying so that it comes across in your performance.
Key ideas: demonstrate your vocal range - belt and head voice or lower range and classical sound.
show your dramatic range - character piece and dramatic moment
a range of tempos allows you to show movement and rhythm
always take a 3rd/4th option incase they ask to see something else
Finally, always choose songs that you feel comfortable singing, even on a 'bad day'. Know your sheet music or backing track back to front and ALWAYS be nice and thank the Pianist or Sound Technician.