Related Clues:

• Flagship product from 21-Down
• Explanatory material
• Scoring units
• What the starts of 17-, 34- and 61-Across are
• Do, re, mi, e.g.
• Writes down
• Do, re and mi, etc.
• Arpeggio components
• They're taken or passed in class
• Scrapbook
• Item with a sleeve
• The Beatles' 'Revolver' or 'Help!'
• Staff members, and what the circled letters in this puzzle represent
• Some scribbles
• Holder of photographs