Possible Clues:

• Computer user's need
• Computer part
• Typewriter's essential control panel
• A pianist could play this essential sheet
• Item of office equipment is essential, needed by firm's bosses
• Given this, one must hit the right note — it's essential to get on
• Piano or typewriter has one
• Important committee type here
• Console warrior online using this?
• Something to play? Opener not interested, reportedly