Anacrusis – A note or sequence of notes which precede the first strong beat of a musical phrase, particularly at the start of a piece
(Note: Anacrusis is also called the pickup).
To remember what anacrusis means, use the following mnemonic:
I have a knack for ruining my sisters (anacrusis) performances by playing a strange sequence of notes at the start of the songs.
Anacrusis are the first notes that allows a singer or dance performer to organise themselves and gather all their energy to give a strong, correct note for the upcoming first main beat of the bar. It's essentially a couple of warning notes.