When you decide how you want to sing your song, mark your music with the directions so the accompanist knows how to follow you. You can highlight the tempo and dynamic markings to make sure that your accompanist sees them; if none are written in, write them within the piano part. You often see tempo markings above the vocal line.

To make sure that your accompanist sees them, go ahead and write them in the space between the two sets of five lines down in the piano part. If you want to change the style of singing, you need to change what the accompanist plays. Some accompanists are great at this, and you can just ask them to play a piece in the style of a country song even if that’s not what’s written on the page.

The accompanist simply changes the way the chords are played and perhaps changes the rhythm on the page to match your vocal changes. Accompanists who don’t play a lot of contemporary material may be really good at changing the tempo and dynamics, but not so good at making up an accompaniment that sounds like a pop song.

Don’t assume that an accompanist can change the accompaniment on the fly. If you want to change a familiar song at an audition to sound very different than how it’s normally played and sung, ask in advance.