(Music Sales America). The Concert Performer Series brings you 18 well-known piano pieces, beautifully presented on strong, high-sheen card, complete with a special online media which contains audio to help you practise for a truly great performance. Audio is accessed online using the unique code inside the book and can be streamed or downloaded. The audio files include PLAYBACK+, a multi-functional audio player that allows you to slow down audio without changing pitch, set loop points, change keys, and pan left or right.