For the performance, you can choose which song you'd like to perform yourself.
You are free to choose which piece you'd like to perform at the concert.
You can choose what you'd like to play at the concert.
「発表会で演奏したい曲を自分自身で自由に選曲できる」＝ For the performance, you can choose which song you'd like to perform yourself. / You are free to choose which piece you'd like to perform at the concert. / You can choose what you'd like to play at the concert.
ボキャブラリー
発表会 ＝ performance, concert
演奏したい ＝ perform, play
曲 ＝ song, piece
選曲する ＝ choose
like to 動詞 ＝ したい
free to ＝ ～が自由
yourself ＝自分
イギリス 
