If you are using PlayScore 2 as an accompanist, you may not want the app to start playing until you are ready.  This is the purpose of the Count-in feature.  Count-in will tap out one or more measures before the music starts, giving you time to pick up your instrument.

Tap the Count-in iconCount-In 2nd from left at the bottom.  Tap+/- to set the number of measures to be counted.  If the music has a pick-up bar or anacrusis, Count-in will also tap the beats prior to the first notated beat.

While one or more measures of Count-in are set they will be played before the music starts wherever you tap in a score.

(Apple devices only)