Orchestral work by Austrian composer Joseph Hayden so named for the surprise
a startlingy loud chord that interrupts the other wise soft and gentle flow of the second movement. The distinctive feature did not appear in the original score
Improv is when you do something that is not planned or written in the music. For instance a singer can provide improv by doing a run or adding in an extra note or something of that nature. improv is mostly a drama term that is used for an unscripted scene between two or more actors, typically they are given a topic and thrown into a scene with no prep time.
