The ear should be prepared for the change to every note by the note preceding it. The mastery of this concept is conditional upon mastery of the previous three skills. Equally, avoid grotesque exaggerations. It is always interesting to hear a musical phrase that tells a story. No two measures should ever be played exactly the same, especially if they have exactly the same notes.
Popular music is rather boring for it thrives on repetition and similarity.
Classical music promotes subtleties, differences and unity through diversity. After a bell or gong has been struck, the tone naturally grows, changes, and diminishes in texture, sonority and timbre. Instrumental musicianship should never sound like an electronically-generated tone that has no warmth, feeling or direction. A musical line should have direction without interruption. For example, think about how annoying it is to listen to a person who rambles, or, in the middle of a sentence, becomes silent or pauses for several seconds.