To know the substantials and side issues of the piece you are playing.

Important, don't you agree? But too often practicing/rehearsing will not transcend reproducing.

Getting an overview 

• Are there clear points of change and (as a result of that) episodes?
• If so: how many and where do they start and end approximately? We call these points of segmentation and sections. Annotate them in your score.
• Points of segmentation have grades. To begin with discern between three categories: big (V), medium (v) and Small ( | ).
• Determine with which musical means segmentation is achieved (melody/harmony, metre/rythm, dynamics, timbre, articulation).
• Are there few points of segmentation and as a result of that no clear episodes? In that case we are possibly dealing with gradual musical processes.
• Can we perceive change? If so, with what musical means and to what extent?
• Are certain patterns to be recognized in changes? If so, how and with what musical means?
• If we are dealing with gradual change, do those changes have a certain goal or purpose?
• Are things added, omitted, or stays the used material (globally) the same? 
• What can you say about the amount of tension?
• If tension is increasing or decreasing how is this effect achieved (musical means)?
• Does the music move towards or away from a certain point?

• Is there repetition?
  
• If so, where and with what musical means?
• IIs there immediate repetition or repetition at a distance
• What can you say about time intervals between repetitions?
• Are there any contrasts?
• If so, where approximately, how big and with what musical means?Zo ja: waar ongeveer, hoe groot en met welke middelen?
• Is there variation?
• If so: how and with what musical means? 
• What can you say about the texture (relation between parts/voices: polyphonic, homophonic, heterophonic, ...)?

Positioning the composition within the total output of the composer, his contemporaries and the musical climate/context.